Royal Dutch Shell has agreed to sell a 33.24 percent stake in Japanese refiner Showa Shell Sekiyu to Idemitsu Kosan for about ¥169 billion, the global oil conglomerate said Thursday.

The deal for 125.3 million shares in Showa Shell Sekiyu KK is almost 23 percent more than the closing price Wednesday, according to data compiled by Bloomberg. The deal is scheduled to be completed in 2016. The Dutch firm will retain a 1.8 percent holding in Showa Shell.

"The sale is consistent with Shell's strategy to concentrate its downstream footprint on a smaller number of assets and markets where it can be most competitive," John Abbott, Shell's downstream director, said in a statement. "Idemitsu is an established and successful company and is well positioned to take up Shell's shareholding."