June 29 (Reuters) - Wejo, a British auto data startup backed by General Motors Co (GM.N), said on Tuesday that Microsoft Corp (MSFT.O) and insurer Sompo Holdings Inc (8630.T) will invest $25 million in the company. The investment comes as Wejo prepares to go public later this year through a reverse merger with blank-check company Virtuoso Acquisition Corp (VOSO.O). The deal was announced last month and valued the startup at $800 million including debt. read more Microsoft and Sompo join General Motors and data analytics firm Palantir Technologies Inc (PLTR.N) as part of Wejo"s private investment in public equity (PIPE) financing, which now stands at $125 million. Manchester-based Wejo organizes data from almost 11 million vehicles connected to the internet for clients such as GM, Hyundai Motor Co (005380.KS) and Daimler (DAIGn.DE). Reporting by Ankit Ajmera in Bengaluru; Editing by Shounak Dasgupta Our Standards: The Thomson Reuters Trust Principles.