(Adds analyst comment, details on results, background; updates shares)
By Manas Mishra
Jan 29 (Reuters) - Allergan Plc on Tuesday forecast 2019 revenue below expectations on looming competition for some of its top drugs, and shelved plans to sell its women's health business.
The Botox maker's shares fell 6 percent to $149.20 in early trading.
Chief Executive Officer Brent Saunders put the company's women's health and infectious disease units on the block in May to focus on growing its core businesses that include medical aesthetics and eye care.
"For Women's Health, we have concluded that the highest value proposition for this business at this time is to continue managing it and optimizing it," Saunders said on a post-earnings call with analysts.
The CEO also said the anti-infectives business would "more likely than not" be sold over the near term.
In the fourth quarter, the company recorded pretax impairment charges of $5.4 billion, including a goodwill write-off related to the anti-infectives unit and a charge from lower-than-expected sales of its double chin treatment Kybella, which it bought at a premium of 24 percent in 2015.
"Given questions around the past deals and management's ability to execute, we think the Street will likely view this large write-off negatively," Credit Suisse analyst Vamil Divan said in a note.
Allergan has warned that profits will be hurt once generics of Restasis hit the market, after a bid to protect that drug's patents met regulatory scrutiny. Once a drug begins facing competition from multiple generic versions, it can quickly lose more than 80 percent of sales.
Sales of Restasis, the company's second-most important drug, fell 17.7 percent, while sales of Botox, Allergan's best-selling product, rose 9.4 percent.
Botox's market-leading position in aesthetics and as an anti-wrinkle treatment has helped the company power past analysts' profit estimates for much of the past, but concerns remain about the competitive threat from two smaller companies' upcoming rival products.
Allergan said last year it was doubling its investment in direct-to-consumer ad spending and beefing up its sales force as companies like Revance Therapeutics Inc and Evolus Inc vie to wrest market share with rival treatments to Botox.
Excluding items, Allergan earned $4.29 per share in the fourth quarter, beating analysts' expectations of $4.15, according to Refinitiv data.
The company, which authorized a new $2 billion share buyback program, said net revenue fell 5.7 percent o $4.1 billion.
Allergan forecast 2019 revenue of $15.00 billion to $15.30 billion, compared with analysts' estimates of $15.40 billion. (Reporting by Manas Mishra in Bengaluru; Editing by Maju Samuel and Sweta Singh)