Apparel maker Lands' End said last week it was working to resolve allegations of anti-union discrimination by a foreign supplier.

The Wisconsin-based company, owned by department store group Sears, Roebuck & Co, has in recent weeks seen a number of US universities fail to renew Lands' End licensing agreements as a result of the allegations.

According to UW-Madison chancellor's special assistant John Wiley, a factory in El Salvador that supplies to Lands' End has refused to hire workers because of their union connections.

As such, the university decided not to renew its licensing agreement with the company, while other institutions including Northwestern, Georgetown and Duke have taken similar steps.

However, Lands' End spokesman Chris Mordi said the company was working with the Fair Labour Association (FLA) to end the dispute at the Primo factory.

"We've taken the allegations seriously," Mordi said.

While neither Lands' End or the FLA would comment on the ongoing negotiations, a recent report from the labour group said Lands' End had invited nine of the 19 former union-affiliated workers to apply for factory jobs and told them they would be given preference over other applicants for jobs that matched their skills.

The FLA also reported that Lands' End had visited another El Salvadorian factory, Just Garments, and would consider using it as a supplier if it met quality and production standards.