TOKYO (Reuters) - Japanese refiner Idemitsu Kosan Co Ltd (>> Idemitsu Kosan Co., Ltd.) said on Monday it has completed its planned acquisition of 31.3 percent of rival Showa Shell Sekiyu KK (>> Showa Shell Sekiyu KK) from Royal Dutch Shell PLC .

Earlier in the day, Japan's anti-monopoly regulator approved Idemitsu's plan to acquire the stake.

In a filing at the stock exchange, Idemitsu said it paid 1,350 yen a share, or a total of 159 billion yen (1.08 billion pounds).

The refiner had originally planned to buy 33.3 percent from Royal Dutch Shell.

(Reporting by Taiga Uranaka)

Stocks treated in this article : Showa Shell Sekiyu KK, Idemitsu Kosan Co., Ltd.