(Adds detail) LONDON, Jan 31 (Reuters) - British gambling company Rank reported a 23 percent decline in first half profit on Friday, hit by lower customer numbers at its bingo halls. Rank, which is majority-owned by Malaysia's Guoco Group 0053.HK and also operates casinos in Britain, had warned in October that profits would fall short because of the impact of a summer heatwave on its bingo business. "As previously guided, the first half of the current financial year was challenging with like-for-like brand performances down on the same period last year," Chief Executive Ian Burke said in a statement. Rank said pre-tax profit fell 23 percent to 27.7 million pounds ($45.7 million). The company has responded to difficulties in its Mecca bingo and Grosvenor casino businesses by cutting costs and seeking to boost revenues. Rank runs 97 Mecca bingo halls in Britain. It also has 55 casinos in Britain after buying 19 from Gala Coral Group in a 179 million pound deal last year. "Management anticipates operating profit in the second half, excluding the impact of the acquired casinos, will be broadly in line with the comparable period last year," Burke added. ($1 = 0.6062 British pounds) (Reporting by Keith Weir, editing by James Davey) ((keith.weir@thomsonreuters.com)(020 7542 8022)(Reuters Messaging: keith.weir.thomsonreuters.com@reuters.net)(To sign up for our Global Sports Forum chatroom, click on https://forms.thomsonreuters.com/global_sports_forum)) Keywords: RANK/