UPDATE 2-Allergan beats earnings estimates on strong sales of Botox, Restasis

(Adds CEO quote, more details on Restasis results)

Nov 1 (Reuters) - Allergan Plc's third-quarter profit topped Wall Street forecasts on Wednesday, as the drugmaker sold more Botox and benefited from strength in its eye care business that houses dry-eye medicine Restasis.

Allergan has been lobbying hard in recent years to protect Restasis the hallmark of its top-earning eye-care business from being ousted by generic rivals.

It struck a controversial deal with a Native American tribe in September to shield a separate review of Restasis patents by U.S. regulators, drawing the ire of both lawmakers and rival drug companies.

A Texas court last month invalidated Restasis patents on grounds that they cover ideas that are obvious, making it possible for rival generics to hit the market as early as next year.

Allergan has appealed the ruling, Chief Executive Brent Saunders said in a statement on Wednesday.

"If a generic product enters the market, Allergan is ready to mitigate that impact by growing our base business, reducing costs and deploying our balance sheet," he added.

Allergan's strong earnings may not be enough to offset concerns around challenges it is likely to face, including the loss of exclusivity for some of its key drugs and generic competition for Restasis, Cantor Fitzgerald analyst Louise Chen said.

Allergan said it evaluated all of its dry eye-related assets as a result of the court order, and recognized an impairment of $3.2 billion related to Restasis in its latest quarter.

As a result, Allergan reported a net loss of $4.03 billion or $12.07 per share in the third quarter ended Sept. 30, compared with a profit of $15.15 billion or $38.58 per share a year earlier.

Excluding the charge and other items, Allergan earned $4.15 per share and topped analysts' average estimate of $4.05, according to Thomson Reuters I/B/E/S.

Net revenue rose 11.4 percent to $4.03 billion, matching analysts' expectations.

Allergan's medical aesthetics business generated $602.3 million in sales in the quarter, up nearly 55 percent from a year ago, while sales of Restasis came in at $382.3 million, beating Cowen & Co's estimate of $355 million.

Botox, Allergan's best-selling drug, raked in $774.5 million in sales, making up nearly a fifth of overall revenue.

Allergan's shares rose 1.7 percent to $180.25 in premarket trading on Wednesday. (Reporting by Tamara Mathias in Bengaluru; Editing by Anil D'Silva and Sai Sachin Ravikumar)