Four Japanese companies separately said Monday that they won stakes in several energy exploration blocks in the North Sea in a tender held by the U.K. government in May.

JX Nippon Oil & Gas Exploration Corp., the upstream unit of JX Holdings Inc. (5020.TO), won stakes in 18 blocks and will be the operator of five of them, the company said in a statement.

Idemitsu Kosan Co. (5019.TO) won stakes in eight blocks, while Inpex Corp. (1605.TO) and Sumitomo Corp. (8053.TO) each won stakes in three blocks, the companies said.