Lawson Inc., the nation's second-largest convenience store chain, may form a capital alliance with Japan Post Holdings Co. by the middle of the year.

"If such an event were to occur, it would be around this summer," Lawson Chief Executive Officer Takeshi Niinami said in an interview on Bloomberg Television.

Japan Post President Yoshifumi Nishikawa said in February the two companies should hold stakes in each other after they announced plans to operate outlets together.

In 2003, Lawson began installing mailboxes at its stores across Japan.