Microsoft has invested in Cruise, the General Motors driverless car unit, in a $2 billion funding round that gives the autonomous driving company a $30 billion valuation.

Cruise, which was bought by GM for “more than $1 billion” in 2016, when it had just 40 employees, now has almost 2,000 staff and accounts for more than 40 percent of GM’s $71.5 billion market capitalisation.

Its latest investment round puts it head-to-head with Waymo, the Google sister company, as the world’s most valuable autonomous driving start-up. Waymo raised $3.2 billion last year at an undisclosed valuation that two people said to the FT was “more than $30 billion.”