Supporters of compensation plans say they are needed to pay for medical care for those who are paralyzed or otherwise badly injured, to provide income after a vital breadwinner died and to give families enough income so that children are not forced to quit school and go to work.

“Compensation is so important because so many families are suffering — many families don’t have anyone left to support them,” said Kalpona Akter, executive director of the Bangladesh Center for Worker Solidarity. “There’s been a good response from some European brands, but so far none of the U.S. retailers have agreed to pay a single penny for compensation.”

Paul Lister, Primark’s general counsel, said that from the day Rana Plaza collapsed, his company recognized its responsibility. Primark, which says it has already spent more than $3.2 million for aid to the victims, first provided several weeks’ emergency food assistance to 1,300 families, then short-term financial aid and now it is working to develop a compensation fund to help victims for years, even decades.

“We knew we were having clothes made in Rana Plaza — we announced that on the first day,” Mr. Lister said about the April 24 building collapse, which killed 1,129 workers. “When you know where your clothes are made, then you take responsibility for the results of where your clothes are being made. We have said very clearly that we would work to support the workers — and the families of the workers — in our supply chain.”

Primark, whose brands include Atmosphere and Denim Company, was a major customer of New Wave Bottoms, one of the five garment factories inside Rana Plaza. For the last six months, Primark has paid the salaries for not just that factory’s 550 workers but for all 3,600 Bangladeshis who worked inside the building. After setting up a series of help desks for Rana Plaza workers and families to register, Primark paid the salaries to surviving workers or families of the dead.