London (Reuters) - Britain will make an announcement on Wednesday about slot machines in bingo clubs, a government source said on Monday, in a move expected to give the sector a lift by relaxing limits on the number of slot machines. An industry source said the government would announce plans to raise from four the maximum number of 500-pound (USD 980) jackpot slot machines allowed in bingo clubs and was expected to choose from one of three options put to it by operators.