May 9 (Reuters) - Drugmaker Viatris narrowly

missed first-quarter revenue estimates on Thursday, hurt by weak

sales for its older drugs such as cholesterol medication Lipitor

and Norvasc for high blood pressure.

Net sales in its branded drugs unit, which makes up

two-thirds of the company's total revenues, also fell 4.5% to

$2.31 billion.

Viatris ( VTRS ), formed by the merger of Mylan and Pfizer's ( PFE )

Upjohn business, makes generic and key branded drugs such as

erectile dysfunction drug Viagra, anti-anxiety medication Xanax,

epilepsy treatment Lyrica and arthritis treatment Celebrex.

The company last year agreed to divest its over-the-counter

(OTC) drugs, active pharmaceutical ingredients (API) and women's

health businesses. It said in February the expected timing of

the deals closing will impact results for the next few quarters.

On Thursday, CEO Scott Smith said the company has completed

the divestiture of its women's healthcare business, while the

API unit's divestiture will close imminently.

The Canonsburg, Pennsylvania-based company reported revenue

of $3.65 billion for the first quarter, narrowly missing

estimates of $3.69 billion, according to LSEG data.

The company also maintained its annual revenue forecast of

$15.25 billion to $15.75 billion.

On an adjusted basis, it reported a quarterly profit of 67

cents per share, in line with estimates.

Sales of its key global products such as Lipitor fell to

$388.9 million from $417.9 million a year ago. Norvasc recorded

net sales of $176.3 million, compared with $202.7 million a year

ago.