Three weeks after a building collapse in Bangladesh that killed more than 1,100 workers, several of the world’s largest apparel companies – including the retailing giant H&M and Inditex, owner of the Zara chain — agreed on Monday to sign a far-reaching and legally binding plan that requires retailers to help finance fire safety and building improvements in the factories they use in Bangladesh.

Consumer and labor groups hailed the move by Sweden-based H&M – which is the largest purchaser of garments from Bangladesh – as an important step toward improving factory safety in Bangladesh, saying it would increase pressure on other Western retailers and apparel brands to do likewise.

Within hours of H&M's Monday statement, C&A of the Netherlands and two British retailers, Primark and Tesco, also joined in.

The factory safety agreement calls for independent, rigorous factory safety inspections with public reports and mandatory repairs and renovations underwritten by Western retailers. A legally enforceable contract, it also calls for retailers to stop doing business with any factory that refuses to make necessary safety improvements, and for workers and their unions to have a substantial voice in factory safety.