MADRID, March 11 (Reuters) - Spanish telecom operator MasMovil has started talks over a possible merger with the Spanish unit of U.K.-based telecom operator Vodafone, newspaper Expansion reported, citing sources with knowledge of the process. MasMovil, which was taken over by three buyout funds including KKR last year, has set a first valuation of the Vodafone unit at 7.5 billion euros ($8.96 billion), the newspaper said. Expansion did not say who would control the merged entity if a merger proceeded. A MasMovil spokesman said he could not immediately comment, while a spokesman for Vodafone declined to comment. Back in September, MasMovil and its private equity owners denied a previous press report about merger talks between the two rival telecom operators.