Chinese search giant Baidu is set to invest $600 million in Uber, the fast-growing ride-hailing company, according to a source quoted by Bloomberg.
Baidu itself recently said it will announce a major new partnership on Wednesday, but offered no details.
A recent investment round pegs Uber's market value at $40 billion. Uber, based in San Francisco, is now a private company -- its shares do not trade on the major stock markets.
Baidu, based in Beijing and often called "the Google of China," is headed by its founder, the now fabulously wealthy entrepreneur Robin Li.
Last year, Google Ventures invested $258 million in Uber.
Uber already operates in China. The China market, with its huge population, appears ripe for ride-hailing. Despite a slowing economy, China's middle class continues to grow; many people who can't yet afford cars can afford smartphones, and use an app to hail a ride from their richer compatriots.