Chinese tech giant Tencent Holdings Ltd has joined the race, along with rivals such as Baidu Inc and Alibaba Group Holding Ltd, to recruit senior autonomous driving engineers in Silicon Valley.

The Shenzhen, Guangdong province-based company, owner of popular social media app WeChat, is building an autonomous driving research team based in Palo Alto, California, according to job postings on LinkedIn.

"Expert/senior researchers" who "have a strong interest in developing cutting-edge technologies are being recruited. The technologies include simultaneous localization and mapping (SLAM) and localization, machine learning, motion planning, perception and sensor fusion, and behavior prediction," according to a posting on the online job board last month.

Tencent has three offices in the United States－in Palo Alto, Seattle and New York. The company did not immediately respond to a request for further information.

The tech company set up an autonomous driving lab in 2016, with a focus on high-definition maps, positioning solutions and analog simulation, among others.

It launched Tencent Autonomous Driving as an independent brand at the Tencent Global Partner Conference held on Nov 1 in Nanjing, Jiangsu province.

The company has been given the green light by the Shenzhen and Beijing authorities to test autonomous vehicles on the cities' roads. Its Level 3 autonomous vehicle－which means the vehicle can perform fully-automated driving on certain sections of road－hit the road this year.

Baidu ventured into the autonomous driving space before its two rivals Alibaba and Tencent. The biggest search engine in China set up a base in Silicon Valley in 2011. It already has an autonomous vehicle testing permit in California.

This month, Baidu and Chinese carmaker FAW Hongqi unveiled a Level 4 autonomous driving passenger car in Beijing, which means the car can drive autonomously in most conditions without human intervention. The cars will enter mass production by the end of 2019.

Alibaba set up artificial intelligence labs in 2016. In April, the Chinese e-commerce giant confirmed it was testing its own autonomous technologies.

The company launched a Level 4 self-driving logistics vehicle at a computing conference in September in Hangzhou, Zhejiang province.

Developed by Alibaba AI Labs, the vehicle is designed for urban logistics delivery. The Hangzhou authorities have issued a license for Alibaba to road-test its autonomous vehicles.