Dollar Tree said on Wednesday that it is considering a sale or spinoff of Family Dollar, which has struggled with its operation for years.

There are about 8,000 Family Dollar stores, and Dollar Tree, which owns Family Dollar, said in March that it would close nearly 1,000 of them. In February, the U.S. Justice Department fined Family Dollar $41.7 million, the largest-ever financial criminal penalty in a food safety case, for distributing food, drugs, medical devices and cosmetics from a rat-infested warehouse.

Rick Dreiling, chairman and chief executive of Dollar Tree, said in a statement on Wednesday that the “unique needs” of its discount store chains led the company to explore a sale of Family Dollar, which it bought in 2015 in an $8.5 billion deal.

This is a developing story that will be updated.