TOKYO (Reuters) -JX Advanced Metals (JXAM), a wholly owned metals unit of Japan's Eneos Holdings ( JXHGF ), won approval to list its shares in a $3 billion share offering, a regulatory filing showed on Friday, in what would be the nation's biggest IPO in seven years.

JXAM has set a tentative offering price of 862 yen ($5.64) per share ahead of its listing on the Tokyo Stock Exchange on March 19. The final pricing is set for March 10.

Eneos ( JXHGF ), Japan's largest oil refiner, plans to sell 465.2 million shares of JXAM with an overallotment option of up to 69.8 million shares.

The share sale would allow Eneos ( JXHGF ) to raise as much as 461 billion yen ($3.01 billion), according to Reuters' calculations, giving the business a market value of 800 billion yen.

Reuters reported earlier this week Eneos ( JXHGF ) was seeking to raise at least 400 billion yen through the IPO. The refiner plans to use the proceeds for growth investments and to enhance shareholder returns.

At that size, JXAM would exceed Tokyo Metro's IPO in October, according to LSEG data, and be the largest listing in Japan since SoftBank's telecoms unit in 2018.

JXAM is a leading manufacturer of sputtering targets, which are materials used to create thin metal films during chip production.

The unit's semiconductor materials segment contributed around a third of its 81 billion yen operating income in the last financial year.

JXAM has invested in a new plant for manufacturing sputtering targets in Arizona.

Daiwa Securities, JPMorgan, Morgan Stanley and Mizuho are joint global coordinators on the IPO.

($1 = 152.8600 yen)

(Reporting by Mariko Katsumura and Sam Nussey; Editing by Muralikumar Anantharaman)