(Adds forecast, background)
Jan 30 (Reuters) - U.S. drugmaker AbbVie Inc's revenue beat analysts' estimates for the fourth straight quarter as sales of arthritis drug Humira jumped nearly 11 percent.
The company, however, reported a net loss of $810 million, or 51 cents per share, for the fourth quarter, mainly due to a charge related to its aborted $55 billion deal to buy British drugmaker Shire Plc.
Excluding the charge and other special items, AbbVie earned 89 cents per share. Analysts on average had expected 86 cents per share, according to Thomson Reuters I/B/E/S.
Revenue rose 6.7 percent to $5.45 billion, above the average analyst estimate of $5.36 billion.
Sales of Humira, which AbbVie inherited from Abbott Laboratories in 2013, rose to $3.36 billion in the fourth quarter ended Dec. 31.
AbbVie kept its 2015 forecast from Jan. 8 unchanged.
The company expects 2015 earnings of $4.25-$4.45 per share, up sharply from last year's $3.32 per share, citing demand for its all-oral Viekira Pak hepatitis C treatment and growing sales of Humira.
Analysts expect Viekira Pak, approved by U.S. regulators in December, to eventually command about 25 percent of the lucrative hepatitis C market.
The drug competes with Gilead Sciences Inc's Harvoni, a combination pill that has a list price of $93,400 for 12 weeks of treatment.
Pharmacy benefit manager Express Scripts has backed AbbVie's therapy, saying it got a significant price discount compared with Harvoni and Sovaldi, a predecessor treatment from Gilead that is one of the two components of Harvoni.
Insurers UnitedHealth Group Inc, Aetna Inc, Humana Inc and Anthem Inc have all backed Gilead, as has pharmacy benefit manager CVS Health. (Reporting by Ransdell Pierson; and Vidya L Nathan in Bengaluru; Editing by Don Sebastian and Saumyadeb Chakrabarty)