BEIJING (AFP) ― Chinese search engine Baidu, the country’s equivalent of Google, announced Wednesday it has bought a stake in Uber for an undisclosed sum, as the controversial U.S. web-based taxi app seeks to expand into an already crowded market.

Baidu will also link users of its mapping and search functions with Uber drivers, the two companies announced at a ceremony in Beijing. The investment has previously been reported to be as much as $600 million, according to state-run China National Radio.

“Our efforts here in China are unique and will continue to be, let’s call it, more unique than anywhere else,” Uber’s CEO Travis Kalanick said at a press conference after the signing ceremony.

“You have to do things differently here in China,” he said, without elaborating.

Uber, which connects riders and local drivers, currently operates in nine cities across China, including the capital Beijing and financial hub Shanghai.