The Beijing-based firm operates China's main search engine and has long been a key player in the Chinese tech industry, up against rivals including Tencent and Alibaba.

Baidu derives a large part of its revenue from advertising, a sector vulnerable to fluctuations in consumer sentiment, and has sought to diversify with cloud computing, self-driving cars and AI.

The firm said revenue dipped two percent year-on-year in the fourth quarter, rounding off an overall annual decline of one percent.

"While navigating near-term pressures, we are confident that our strategic AI investments will drive meaningful progress and foster long-term success", He Junjie, Baidu's interim chief financial officer, said in the Tuesday filing.

In a more positive sign, net income rose 100 percent in the fourth quarter to $711 million.

That helped Baidu post an annual net income of $3.26 billion, up 17 percent from 2023.

Last year was "a pivotal year in our ongoing transformation from an internet-centric to an AI-first business", Baidu co-founder and CEO Robin Li said.

Baidu shares in Hong Kong slid around seven percent Monday after Li was not spotted at a rare meeting between President Xi Jinping and business leaders in Beijing. They ended slightly higher on Tuesday.