Labour strikes are rare in Japan, and if the threatened action goes ahead, it would be the first at a major department store in about 60 years, local media reported. Sogo & Seibu's labor union announced the strike notice at a news conference. Japan-based Seven & i, operator of the world's largest convenience store chain, last year agreed to sell Sogo & Seibu to Fortress Investment Group. But the deal has been delayed amid opposition from workers, and company management canceled a meeting for Friday last week where it was to finalize the sale, Kyodo reported. Seven & i Holdings confirmed its unit had received the strike notice and said it was reviewing the union's requests. Negotiations will continue, it said. If the talks break down, about 900 union members at Seibu's flagship store in Tokyo's Ikebukuro district will strike on Thursday, a union member said. He said the union settled on Thursday because it believed Seven & i was looking to complete the sale of the unit the following day.