(Adds details on ad revenue)
Feb 27 (Reuters) - Discovery Communications Inc's revenue topped analysts' forecasts in the fourth quarter as the owner of Discovery Channel and Animal Planet benefited from higher advertising income across its networks.
Discovery said on Tuesday advertising revenue from its U.S. networks rose 8 percent in the quarter ended Dec. 31, while ad revenue from international networks climbed 11 percent.
The company also said it expects to close its $14.6 billion acquisition of U.S. peer Scripps Network Interactive by the end of the first quarter of 2018. Discovery is awaiting the completion of a review by regulators in Ireland.
Discovery said its net loss was $1.14 billion in the fourth quarter, compared to a profit of $304 million, a year earlier. Results included a $1.3 billion one-time goodwill impairment charge.
Excluding one-time items, Discovery earned 47 cents per share.
Revenue rose 11.5 percent to $1.86 billion, beating analysts' estimates of $1.79 billion, according to Thomson Reuters I/B/E/S.
Shares of Silver Spring, Maryland-based Discovery rose 1.3 percent in premarket trading on Tuesday. (Reporting by Sonam Rai in Bengaluru; Editing by Sai Sachin Ravikumar)