Lawson Inc. has decided to scrap a plan to acquire all shares of its smaller rival, am/pm Japan Co., sources close to the move said.

Negotiations have broken down between Rex Holdings Co., the parent firm of am/pm Japan, and the U.S. company which owns am/pm's trademark rights, the sources said.

Lawson, Japan's second-largest convenience store chain operator, agreed with Rex Holdings in February to buy all shares of am/pm Japan for ¥1 in March while taking over am/pm Japan's interest-bearing debts of ¥20 billion.

In early April, Lawson said it postponed its acquisition of am/pm Japan because it would take time to complete the details with Rex Holdings.