TOKYO, Dec 23 (Reuters) - The secretary-general of a Japanese ruling party lawmakers' group on chip strategy said on Friday he believed Taiwan's TSMC is considering a second chip plant in Japan, and that Japan needs to create a conducive environment for such decision.

Taiwan Semiconductor Manufacturing Co (TSMC) is building a major chip plant in Japan, with Sony Group Corp and auto parts maker Denso Corp each taking a minority stake in the $8.6 billion project.

The Japanese government, which has sought to boost domestic microchip production, plans to offer the project up to 476 billion yen ($3.59 billion) in subsidy.

"I believe TSMC is looking into further investments in Japan. We need to create an environment that would make them think they want to do advanced projects with us," Yoshihiro Seki, secretary general of the lawmakers' group told Reuters in an interview.

The group, which has about a hundred Liberal Democratic Party lawmakers as its members, has been a force behind Japan's recent moves to secure microchip supplies and strengthen its semiconductor industry, including the construction of the TSMC plant in western Japan. ($1 = 132.6700 yen) (Reporting by Kiyoshi Takenaka; Editing by Muralikumar Anantharaman)