SINGAPORE, July 26 (Reuters) - Indonesian media conglomerate Elang Mahkota Teknologi (Emtek) is investing $375 million in ride-hailing and payment firm Grab"s Indonesia unit, the companies said in a statement on Monday, in what they described as a "strategic alliance." The deal is the latest tie-up between Singapore-headquartered Grab, the region"s biggest ride-hailing and food delivery firm, and Southeast Asian conglomerates, including a strategic investment by Thailand"s Central Group in 2019. The Indonesian conglomerate holds stakes in media companies as well as a controlling stake in e-wallet DANA and a stake in e-commerce site Bukalapak. Two sources told Reuters that the deal is in part intended to lead to a shake-up in the digital payments sector and help Grab increase its stake in e-wallet OVO. Reuters reported in 2019, citing sources, that OVO and DANA were in talks to merge. Grab, OVO, DANA, and Emtek did not immediately answer requests for comment.