According to a report in Yahoo Finance quoting a source with direct knowledge of the matter, on September 1st, Seven & i will sell department store unit Sogo & Seibu which is expected to put into action a planned walkout at a flagship location. It will be the first major strike in Japan in decades.

Seven & i, the Japanese-based operator of the largest convenience store chain in the world already had entered into an agreement to sell its loss-producing Sogo & Seibu subsidiary to U.S. fund Fortress Investment Group, however opposition from workers had delayed the deal from being finalized.

According to a union member, the union intends to put the planned strike into effect on Thursday at the flagship Seibu Ikebukuro store in Tokyo.

Disputes over labor issues, and even more so, strikes, are extremely uncommon in Japan. According to Japan’s largest industrial union, UA Zensen, it has been 61 years since there has been a strike at a major department store in the country, and that lasted for less than a day.

Seven & i’s plan is for its board to meet Thursday, to make an official decision on the sale, according to a person with direct knowledge of events. The source requested anonymity as the plan is not public knowledge.

In its negotiations with management, Seibu & Sogo’s union had issued an August 29th deadline to Seven & i to abandon its plan to sell the company on September 1st.

According to the union, it has received no reply, and so the strike will begin Thursday at the flagship location, which employs about 900 union members.

Sogo & Seibu has announced they will close the store temporarily on Thursday.

The source said that although Fortress initially planned to spend about 250 billion yen on acquiring the company, it is likely the price was lowered to about 220 billion yen.