UPDATE 2-Pfizer raises 2019 forecast on surging cancer drug sales

(Adds background, details on quarter, updates share price)

Oct 29 (Reuters) - Pfizer Inc posted third-quarter profit well above analysts' estimates on higher sales of cancer drug Ibrance and arthritis medicine Xeljanz, encouraging the largest U.S. drugmaker to lift its earnings forecast for the year.

Shares of the company rose 3% before the opening bell on Tuesday as the results suggested that Chief Executive Officer Albert Bourla's efforts to slim down the sprawling drugmaker were paying off.

Pfizer announced in July it would separate its off-patent branded drugs business and combine it with generic drugmaker Mylan NV, allowing it to focus on its more profitable drugs such as Ibrance and Xeljanz.

Bourla said on Tuesday Pfizer would become a "smaller, science-based company" following the Mylan deal, which is expected to close next year.

Pfizer raised its 2019 adjusted earnings per share forecast to between $2.94 and $3.00, from a prior estimate of $2.76 to $2.86. Analysts on average were expecting $2.82 per share, according to Refinitiv IBES.

J.P.Morgan analyst Chris Schott said the "solid" performance from Pfizer's core products shifts focus to the long-term sustainability of profit margins.

Ibrance sales rose 25% to $1.28 billion in the quarter, ahead of the average consensus of $1.20 billion, according to Morgan Stanley's estimates.

Xeljanz, which is approved to treat several conditions including rheumatoid arthritis, brought in sales of $599 million, beating the consensus estimate of $537 million.

The company also said sales of its patented medicines benefited from demand in emerging markets, which contribute about a quarter of Pfizer's total sales.

Net income attributable to Pfizer's shareholders rose nearly 87% to $7.68 billion, or $1.36 per share, as the company recognized a gain of $8.1 billion after closing its consumer health joint venture with Britain's GlaxoSmithKline Plc.

Excluding special items, Pfizer earned 75 cents per share, easily beating the average estimate of 62 cents.

Total revenue fell about 5% to $12.68 billion as sales of pain treatment Lyrica, which recently lost patent protection in the United States, more than halved to $527 million. (Reporting by Tamara Mathias and Aakash Jagadeesh Babu in Bengaluru Editing by Saumyadeb Chakrabarty)