Moody’s: A2/Stable

Standard & Poor’s: AA-/Stable

Ratings are not a recommendation to purchase, hold or sell notes, inasmuch as the ratings do not comment as to market price or suitability for a particular investor. The ratings are based upon current information furnished to the rating agencies by sanofi-aventis S.A. and information obtained by the rating agencies from other sources. The ratings are only accurate as of the date thereof and may be changed, superseded or withdrawn as a result of changes in, or unavailability of, such information, and therefore a prospective purchaser should check the current ratings before purchasing the notes. Each rating should be evaluated independently of any other rating.

BNP PARIBAS

BofA Merrill Lynch

J.P. Morgan

SOCIETE GENERALE

Credit Agricole CIB

Deutsche Bank Securities

HSBC

RBS

Santander

With respect to any interest determination date, LIBOR will be the rate for deposits in U.S. dollars having a maturity of three months commencing on the interest reset date that appears on the designated LIBOR page as of 11:00 a.m., London time, on that interest determination date (as defined above). If no rate appears, LIBOR, in respect of that interest determination date, will be determined as follows: the calculation agent will request the principal London offices of each of four major reference banks in the London interbank market (which may include the calculation agent, the paying agents or their affiliates), as selected by the calculation agent (after consultation with the Issuer), to provide the calculation agent with its offered quotation for deposits in U.S. dollars for the period of three months, commencing on the interest reset date, to prime banks in the London interbank market at approximately 11:00 a.m., London time, on that interest determination date and in a principal amount that is representative for a single transaction in U.S. dollars in that market at that time. If at least two quotations are provided, then LIBOR on that interest determination date will be the arithmetic mean of those quotations (rounded if necessary to the nearest one hundred-thousandth of a percentage point, with 0.000005 being rounded upwards). If fewer than two quotations are provided, then LIBOR on the interest determination date will be the arithmetic mean (rounded if necessary to the nearest one hundred-thousandth of a percentage point, with 0.000005 being rounded upwards) of the rates quoted at approximately 11:00 a.m., New York City time, on the interest determination date by three major banks in The City of New York (which may include the calculation agent, the paying agents or their affiliates) selected by the calculation agent (after consultation with the Issuer) for loans in U.S. dollars to leading European banks, having a three-month maturity and in a principal amount that is representative for a single transaction in U.S. dollars in that market at that time; provided, however, that if the banks selected by the calculation agent are not providing quotations in the manner described by this sentence, LIBOR determined as of that interest determination date will be LIBOR in effect on that interest determination date. The designated LIBOR page is the Reuters screen “LIBOR01”, or any successor service for the purpose of displaying the London interbank rates of major banks for U.S. dollars. The Reuters screen “LIBOR01” is the display designated as the Reuters screen “LIBOR01”, or such other page as may replace the Reuters screen “LIBOR01” on that service or such other service or services as may be denominated by the British Bankers’ Association for the purpose of displaying London interbank offered rates for U.S. dollar deposits. All calculations made by the calculation agent for the purposes of calculating the interest rate on the Floating Rate Notes shall be conclusive and binding on the holders of Floating Rate Notes, the Issuer and the trustee, absent manifest error.

Ratings are not a recommendation to purchase, hold or sell notes, inasmuch as the ratings do not comment as to market price or suitability for a particular investor. The ratings are based upon current information furnished to the rating agencies by sanofi-aventis S.A. and information obtained by the rating agencies from other sources. The ratings are only accurate as of the date thereof and may be changed, superseded or withdrawn as a result of changes in, or unavailability of, such information, and therefore a prospective purchaser should check the current ratings before purchasing the notes. Each rating should be evaluated independently of any other rating.

BNP PARIBAS

BofA Merrill Lynch

J.P. Morgan

SOCIETE GENERALE

Credit Agricole CIB

Deutsche Bank Securities

HSBC

RBS

Santander

With respect to any interest determination date, LIBOR will be the rate for deposits in U.S. dollars having a maturity of three months commencing on the interest reset date that appears on the designated LIBOR page as of 11:00 a.m., London time, on that interest determination date (as defined above). If no rate appears, LIBOR, in respect of that interest determination date, will be determined as follows: the calculation agent will request the principal London offices of each of four major reference banks in the London interbank market (which may include the calculation agent, the paying agents or their affiliates), as selected by the calculation agent (after consultation with the Issuer), to provide the calculation agent with its offered quotation for deposits in U.S. dollars for the period of three months, commencing on the interest reset date, to prime banks in the London interbank market at approximately 11:00 a.m., London time, on that interest determination date and in a principal amount that is representative for a single transaction in U.S. dollars in that market at that time. If at least two quotations are provided, then LIBOR on that interest determination date will be the arithmetic mean of those quotations (rounded if necessary to the nearest one hundred-thousandth of a percentage point, with 0.000005 being rounded upwards). If fewer than two quotations are provided, then LIBOR on the interest determination date will be the arithmetic mean (rounded if necessary to the nearest one hundred-thousandth of a percentage point, with 0.000005 being rounded upwards) of the rates quoted at approximately 11:00 a.m., New York City time, on the interest determination date by three major banks in The City of New York (which may include the calculation agent, the paying agents or their affiliates) selected by the calculation agent (after consultation with the Issuer) for loans in U.S. dollars to leading European banks, having a three-month maturity and in a principal amount that is representative for a single transaction in U.S. dollars in that market at that time; provided, however, that if the banks selected by the calculation agent are not providing quotations in the manner described by this sentence, LIBOR determined as of that interest determination date will be LIBOR in effect on that interest determination date. The designated LIBOR page is the Reuters screen “LIBOR01”, or any successor service for the purpose of displaying the London interbank rates of major banks for U.S. dollars. The Reuters screen “LIBOR01” is the display designated as the Reuters screen “LIBOR01”, or such other page as may replace the Reuters screen “LIBOR01” on that service or such other service or services as may be denominated by the British Bankers’ Association for the purpose of displaying London interbank offered rates for U.S. dollar deposits. All calculations made by the calculation agent for the purposes of calculating the interest rate on the Floating Rate Notes shall be conclusive and binding on the holders of Floating Rate Notes, the Issuer and the trustee, absent manifest error.

October 31, 2011 (if our pending exchange offer in relation to Genzyme Corporation has not been consummated under the related merger agreement between us and Genzyme Corporation on or before September 30, 2011) or 30 days after the merger agreement between us and Genzyme Corporation is terminated (if, prior to the exchange offer being consummated, the merger agreement is terminated at any time), as more fully described in the preliminary prospectus supplement.

Ratings are not a recommendation to purchase, hold or sell notes, inasmuch as the ratings do not comment as to market price or suitability for a particular investor. The ratings are based upon current information furnished to the rating agencies by sanofi-aventis S.A. and information obtained by the rating agencies from other sources. The ratings are only accurate as of the date thereof and may be changed, superseded or withdrawn as a result of changes in, or unavailability of, such information, and therefore a prospective purchaser should check the current ratings before purchasing the notes. Each rating should be evaluated independently of any other rating.

BNP PARIBAS

BofA Merrill Lynch

J.P. Morgan

Deutsche Bank Securities

HSBC

RBS

With respect to any interest determination date, LIBOR will be the rate for deposits in U.S. dollars having a maturity of three months commencing on the interest reset date that appears on the designated LIBOR page as of 11:00 a.m., London time, on that interest determination date (as defined above). If no rate appears, LIBOR, in respect of that interest determination date, will be determined as follows: the calculation agent will request the principal London offices of each of four major reference banks in the London interbank market (which may include the calculation agent, the paying agents or their affiliates), as selected by the calculation agent (after consultation with the Issuer), to provide the calculation agent with its offered quotation for deposits in U.S. dollars for the period of three months, commencing on the interest reset date, to prime banks in the London interbank market at approximately 11:00 a.m., London time, on that interest determination date and in a principal amount that is representative for a single transaction in U.S. dollars in that market at that time. If at least two quotations are provided, then LIBOR on that interest determination date will be the arithmetic mean of those quotations (rounded if necessary to the nearest one hundred-thousandth of a percentage point, with 0.000005 being rounded upwards). If fewer than two quotations are provided, then LIBOR on the interest determination date will be the arithmetic mean (rounded if necessary to the nearest one hundred-thousandth of a percentage point, with 0.000005 being rounded upwards) of the rates quoted at approximately 11:00 a.m., New York City time, on the interest determination date by three major banks in The City of New York (which may include the calculation agent, the paying agents or their affiliates) selected by the calculation agent (after consultation with the Issuer) for loans in U.S. dollars to leading European banks, having a three-month maturity and in a principal amount that is representative for a single transaction in U.S. dollars in that market at that time; provided, however, that if the banks selected by the calculation agent are not providing quotations in the manner described by this sentence, LIBOR determined as of that interest determination date will be LIBOR in effect on that interest determination date. The designated LIBOR page is the Reuters screen “LIBOR01”, or any successor service for the purpose of displaying the London interbank rates of major banks for U.S. dollars. The Reuters screen “LIBOR01” is the display designated as the Reuters screen “LIBOR01”, or such other page as may replace the Reuters screen “LIBOR01” on that service or such other service or services as may be denominated by the British Bankers’ Association for the purpose of displaying London interbank offered rates for U.S. dollar deposits. All calculations made by the calculation agent for the purposes of calculating the interest rate on the Floating Rate Notes shall be conclusive and binding on the holders of Floating Rate Notes, the Issuer and the trustee, absent manifest error.