LONDON, Oct 17 (Reuters) - Gambling firm Rank Group RNK.L warned its first half profit will be lower than last year, dragging down its full-year expectations after revenues fell during the summer and a disappointing performance at its bingo chain Mecca. Rank, majority-owned by Malaysia's Guoco Group 0053.HK , said it will be taking action to cut costs after like-for-like revenues fell 7 percent in the 15 weeks to Oct. 13. "The board anticipates operating profit for the full year to be marginally below market expectations," Rank said in a trading statement, forecasting a stronger second half to its financial year. (Reporting by Lorraine Turner; editing by Keith Weir) ((lorraine.turner@thomsonreuters.com)(+44 207 542 9597)(Reuters Messaging: lorraine.turner.thomsonreuters.com@reuters.net))