SINGAPORE - Carrefour has launched the sale of units in Malaysia, Singapore and Thailand, sources with direct knowledge of the matter told Reuters, in a deal that could raise around $1 billion for the French retailer.

Carrefour is working with investment banks Goldman Sachs and UBS on the auction, which is expected to generate interest from both corporate buyers and private equity firms, the sources said on Monday.

Carrefour, Goldman and UBS declined to comment.

The sources declined to be identified as the sale process was still not public. The auction is in its early stages, the sources said, and like any sale process could change at any time.

Carrefour, the world's second-biggest retailer, has exited Japan and Korea over the years to focus on bigger and fast-growing markets such as India.

The French group, like many other retailers in Europe and the United States, has been struggling due to challenging economic conditions.

The asset could be attractive for other global retailers that are expanding into Asia, the sources said.

Indonesia's Para Group, which has banking, media and retail interests, has said it aimed to raise more than $350 million from a global bond this year to buy a 40 percent stake in Carrefour's local unit.

Trans Corp, the media, entertainment, lifestyle and retail unit of Para Group, wants to increase its stake in PT Carrefour Indonesia from 40 percent to 100 percent.