TOKYO, Sept 16 (Reuters) - China's antitrust regulator has approved Bain Capital's deal to buy Hitachi Metals, its website said on Friday, clearing a major hurdle for the multibillion-dollar acquisition.

Hitachi Metals announced last year that a consortium led by global private equity firm Bain Capital would buy all the shares of the Hitachi subsidiary for 817 billion yen ($5.7 billion).

The planned deal was for the Bain-led consortium to offer 2,181 yen per share to buy the 47% of Hitachi Metals not owned by Hitachi and spend a further 382 billion yen acquiring Hitachi's 53% stake.

A Hitachi Metals spokesman said the company would make an announcement when the buyer decides to start the planned tender offer. He declined to comment on the Chinese approval.

Hitachi Metals initially expected the tender offer to start in late November 2021, but it was pushed back because of delays to antimonopoly reviews overseas.

The Chinese watchdog's website said the deal was approved on Sept. 7.

Shares in Hitachi Metals rose 0.6% on Friday after a 3% gain the previous day. ($1 = 143.3000 yen) (Reporting by Beijing newsroom and Makiko Yamazaki in Tokyo Editing by Jacqueline Wong and David Goodman)