Hitachi Metals announced last year that a consortium led by global private equity firm Bain would buy all the shares of the Hitachi Ltd metals subsidiary for 817 billion yen ($5.70 billion).
The closing of the deal had been pushed back due to a delay in antimonopoly reviews overseas.
The website said the deal had been approved on Sept. 7.
($1 = 143.3000 yen)
(Reporting by Beijing newsroom and Makiko Yamazaki in Tokyo; Editing by Jacqueline Wong)