Alphabet Google and Nvidia Corp. have expressed concerns to the Federal Trade Commission about Microsoft Corp.’s acquisition of Activision Blizzard Inc., adding fuel to the government’s case against the $69 billion deal, according to people familiar with the matter. The companies joined Sony Group Corp. in raising issues with the transaction, which the FTC sued to block in December. The commission has argued that the deal would hinder competition in the video-game industry and has scheduled an in-house trial for August. Either company could be called to testify as part of the FTC trial.