Uber Technologies Inc. late Thursday announced a $1 billion investment in its self-driving-vehicle unit, just weeks ahead of its highly anticipated IPO. "Excited to announce Toyota, Denso and the SoftBank Vision Fund are making a $1B investment in @UberATG, as we work together towards the future of mobility," Chief Executive Dara Khosrowshahi tweeted . Denso /zigman2/quotes/201343434/delayed JP:6902 +0.54% , a Japanese auto-parts maker, and Toyota /zigman2/quotes/203803129/delayed JP:7203 -0.61% will contribute about $667 million, while SoftBank's /zigman2/quotes/207303954/delayed JP:9984 -1.60% Vision Fund will chip in about $333 billion, CNBC reported . The investment values Uber's Advanced Technologies Group at $7.25 billion, according to Dow Jones Newswires. Uber is expected to go public in early May.