Jan 2 (Reuters) - Chinese internet search giant Baidu 9888.HK said on Friday its AI chip unit Kunlunxin has confidentially filed a listing application with the Hong Kong stock exchange on January 1, paving the way for a spin-off and separate listing.

Baidu ADRs surged 10% in overnight trading.

Reuters had earlier reported that Kunlunxin was planning for a Hong Kong initial public offering after completing a fundraising that valued it at 21 billion yuan ($3 billion).

China is pushing to develop domestic alternatives to U.S. semiconductors amid escalating Washington export restrictions on advanced chips, and several other Chinese AI chip companies have announced public share debuts.

Earlier this week, Chinese AI startup MiniMax said it expects to raise up to HK$4.19 billion ($538 million) in its Hong Kong offering, and semiconductor designer Shanghai Biren Technology 6082.HK raised HK$5.58 billion in its public offering, according to an exchange filing.

Semiconductor specialists OmniVision Integrated Circuits 603501.SS and GigaDevice Semiconductor 603986.SS have also started bookbuilding for IPOs, aiming to raise about $600 million each.

Hong Kong raised $36.5 billion from 114 new listings in 2025, its strongest year since 2021, and more than triple the $11.3 billion raised in 2024, LSEG data shows.

After the proposed spin-off, Kunlunxin is expected to remain a subsidiary of Baidu, the company said.

Details such as the offering size and structure have not been finalised yet, it said.

Founded in 2012 as an internal business unit developing AI chips for Baidu, Kunlunxin has since become independently operated, although Baidu retains a controlling stake.

Kunlunxin mainly supplies chips to Baidu but has expanded external sales over the past two years.

($1 = 6.9931 yuan)

($1 = 7.7847 Hong Kong dollars)