Three consumer groups have put their support behind the Federal Trade Commisson's (FTC) move to block natural foods retailer Whole Foods Market from acquiring its competitor Wild Oats.

In an amicus brief filed in a federal court in Washington DC on Friday (10 Aug), the Consumer Federation of America, the American Antitrust Institute and the Organization for Competitive Markets said they believed the merger would lead to "higher prices, less service and diminished consumer choice".

The groups said that if the merger was blocked WFM and Wild Oats Markets would expand and compete more aggressively with each other, which would be beneficial for consumers.

The FTC has blocked WFM's US$565m takeover of Wild Oats on competition grounds. A ruling on whether to extend the FTC's injunction blocking the acquisition is expected from the federal court in Washington soon.