LONDON (Reuters) - The UK competition regulator has set an April 20 deadline for a decision on the acquisition of supermarket chain Asda by Britain’s billionaire Issa brothers and TDR Capital. Private equity firm TDR Capital and brothers Zuber and Mohsin Issa agreed in October to buy a majority stake in Britain’s third largest grocer from U.S. group Walmart. The brothers and TDR on Tuesday said they had completed the acquisition, which gave Asda an enterprise value of 6.8 billion pounds ($9.5 billion), though it remains subject to regulatory approval. The Competition and Markets Authority (CMA) launched an inquiry into the deal in December and initially set a Feb. 18 deadline for a so-called Phase 1 but then stopped the clock on the process while it sought additional documentation. Its inquiry has been complicated by the buyers’ plan to offload Asda’s 322 petrol stations to their own petrol forecourt business, EG Group, for 750 million pounds when the deal is completed. The petrol forecourts sale, under which the stations will continue to be Asda-branded, will be considered by the CMA as part of its review of the Asda acquisition. At the end of the Phase 1 stage, the CMA will either clear the deal or ask for concessions to avoid a more detailed Phase 2 investigation. Competition lawyers expect the deal to be cleared at Phase 1 but with the combined group having to dispose of some petrol forecourts. The brothers and TDR said they “remain confident of a positive outcome”. In 2019 Walmart’s attempt to sell Asda to rival Sainsbury’s for 7.3 billion pounds was thwarted by the CMA. Asda is due to update on fourth-quarter trading on Thursday. ($1 = 0.7175 pounds)