Solid financial performance

despite substantial generic competition

Expansion of our unparalleled leadership position in Emerging Markets

Improved CHC

presence with key acquisitions in the U.S. and China

Successful launches of Jevtana

®

in the U.S. and Multaq

®

in EU exceeding

expectations

Ownership of 100% of Merial

and planned new JV with Intervet

Faster achievement of cost saving

targets

Sustained flow of financially disciplined business development

activity

Significant advances in transforming our R&D

approach

Possible acquisition of Genzyme

Delivering on our Strategy

Exhibit (a)(5)(O)

Sanofi-aventis Acquisition of Genzyme

Would Be

Beneficial for Both Parties

Creates new platform for 

sustainable growth further

increasing our biotech exposure

Expands footprint in attractive,

growing rare disease market

Increases our U.S. presence and

expands our R&D pipeline of Phase

II and Phase III products

Meets sanofi-aventis value creation

criteria

Preserves strong capital structure

and financial strength

Provides immediate value for all

shareholders

Captures the potential of

Genzyme’s

business and pipeline

and shifts execution risk to sanofi-

aventis

Enhances Genzyme’s

rare disease

business as a center of excellence

Creates more value for Genzyme’s

other product lines within a larger

company with global reach and

resources

As

has

been

previously

disclosed,

representatives

of

sanofi-aventis

and

Genzyme

have

been

engaged

in

discussions

as

to

the

differences

between

sanofi-aventis’

and

Genzyme’s

perspectives

with

respect

to

the

value

of

Genzyme.

These

discussions

have

included

using

a

potential

Contingent

Value

Right

(CVR)

(with

milestone

payments

based

upon

FDA

approval

and

certain

sales

thresholds)

as

part

of

a

resolution

of

the

parties’

differences

with

respect

to

value.

The

discussions

are

continuing,

and

Genzyme

has

been

sharing

certain

non-public

information

with

sanofi-aventis.

Therefore,

sanofi-

aventis

and

Genzyme

have

executed

a

Non-Disclosure

Agreement

with

respect

to

such

non-public

information.

There

is

no

guarantee

that

these

discussions will

continue or that

the parties will

come to an agreement..

Expanding

Growth

Platforms

in 2011

while Facing More Impact from Generics

No H1N1 sales

U.S. healthcare reform and EU price cuts

Full-year generic impact on Ambien®

CR

and Lovenox®

in the U.S. and Taxotere®

in EU

Uncertainty in the U.S. around generics

of

Taxotere®,

a

2

nd

generic

of

Lovenox®

and

generics

of

Eloxatin®

(1)

Double digit sales growth projected for

our Growth Platforms

(2)

Emerging Markets to grow to 1/3 of

Group sales

Launch of Allegra®

OTC in U.S. and

Jevtana®

in EU

€2bn cost savings by end of 2011

Possible acquisition of Genzyme

(1)

Generic

makers

(Teva,

Fresenius

Kabi

(formerly

Dabur),

Sandoz,

Mayne/Hospira,

MN/Par,

Actavis

and

Sun)

required

to

cease

selling

in

the

U.S. since

June

30,

2010

but

litigation

continues.

(2)

Emerging

Markets,

Diabetes

Brands,

Vaccines,

Consumer

Health

Care,

New

Products

and

Animal

Health

-

Note

that

Animal

Health

sales

are

not

consolidated

and

therefore

not

reflected

in

the

percentages

representing

our

Growth

Platforms.