The operator of the Seven-Eleven convenience stores in Japan has sent a formal warning to a franchise owner who filed a request to temporarily shorten operating hours due to a labor shortage, the owner said Friday.

Seven-Eleven Japan Co. has been under scrutiny over its stance toward franchise owners who face difficulty finding employees. The latest revelation comes only months after the company pledged to review its 24-hour operating policy and respond more flexibly to the needs of each outlet.

The franchise owner in Gunma Prefecture, eastern Japan, received the letter Friday from Seven-Eleven Japan President Fumihiko Nagamatsu, who warned of "a serious violation."

The male owner had requested that he close his outlet for five hours through 4 a.m. on July 12.

The company said its franchise owners are required to have an agreement with the chain operator if they are to shorten operating hours, and that in the case in question, the two sides have yet to begin talks.

"I was surprised that (the company) threatened me with the word 'warn,'" the owner said.

Seven-Eleven has been mired in controversy over its 24-hour operating policy after one of its franchise owners in Higashiosaka, western Japan, cut the business hours at his store in February due to a labor shortage, without approval from the franchise operator.

The industry ministry has since urged convenience store operators to draw up an action plan to address problems linked to their operating hours. Many store owners have been struggling to secure labor amid Japan's graying population and have increasingly relied on foreign part-time workers to fill shifts.

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