UPDATE 1-AbbVie boosts 2019 profit outlook as Humira helps beat revenue estimates

estimates@ (Adds share price, compares with analysts' estimates for profit)

Nov 1 (Reuters) - AbbVie Inc posted quarterly sales above estimates on Friday and raised the lower end of its 2019 profit forecast, getting a boost from strong demand for cancer medicine Imbruvica and a lower-than-expected drop in bestseller Humira's revenue.

Shares of the Chicago, Illinois-based drugmaker rose nearly one percent to $80 before the bell.

In June, AbbVie announced a $63 billion deal for Botox-maker Allergan Plc, in a bid to diversify its drug pipeline amid growing threats to Humira's longevity.

The world's top-selling drug, which treats rheumatoid arthritis and psoriasis, has come under pressure from cheaper rivals in Europe and faces patent expiration in the United States - its biggest market, in 2023.

Humira sales was about $20 billion last year and the drug has accounted for the bulk of AbbVie's revenue for years.

In the quarter ended Sept. 30, Humira sales dipped 3.7% to $4.94 billion, hurt by biosimilar competition outside the United States, but beat estimates of $4.89 billion, according to five analysts polled by Refinitiv IBES.

Sales of cancer drug Imbruvica rose nearly 30% to $1.26 billion, ahead of estimates of $1.19 billion.

AbbVie raised the lower end of its 2019 adjusted earnings per share forecast by 8 cents to $8.90, while maintaining the top end at $8.92.

Net earnings fell to $1.88 billion, or $1.26 per share, from $2.75 billion, or $1.81 per share, a year earlier, as research and development costs soared and the company took a charge related to assets acquired as part of an acquisition in 2016.

Excluding items, AbbVie earned $2.33 per share, above the average analyst estimate of $2.30.

Total revenue rose nearly 3% to $8.48 billion, beating estimates of $8.38 billion.

AbbVie said it still expects the deal for Allergan to close early next year and that both companies were cooperating with regulators after receiving a request for more information from the U.S. Federal Trade Commission in September. (Reporting by Tamara Mathias in Bengaluru; Editing by Anil D'Silva)