Jan. 13 (Bloomberg) -- Whole Foods Market Inc., the largest U.S. natural foods grocer, asked competitors in 29 markets for pricing and other confidential data as it seeks to defend its merger with Wild Oats Markets Inc. from a regulator’s review.

Chief Executive Officer John Mackey sent letters to the competing grocers, promising the documents would only be reviewed by attorneys for use in the Federal Trade Commission case and wouldn’t be seen by company employees, said Executive Vice President John Sud. Some competitors said they would send the information and others declined the request, Sud said today during a conference call.

“The information is needed to defend ourselves, on a very tight timeline,” Sud said. He declined to name the companies that received letters. “We’re not here because we want to be.”

Whole Foods, based in Austin, Texas, completed its $565 million purchase of Wild Oats in 2007 after the FTC lost a court bid to block the deal over concerns the combination would hurt consumers. The company has sold 35 of the 110 stores it acquired, shuttered others and re-branded most that remain, Sud said.

An appeals court ruled in July that a district judge should have taken more time to consider the agency’s claims. The FTC then resumed its antitrust review of the merger. A trial before an FTC administrative law judge is set for April 6.

The agency told a federal judge yesterday that Whole Foods, which now has 270 stores, should be ordered to re-brand former Wild Oats stores and keep them as a separate unit until the review is complete.

Prices, Competition

The FTC claimed the acquisition would hurt customers by driving up prices and cutting competition in the market for “premium natural and organic supermarkets.”

Whole Foods rose 49 cents, or 3.9 percent, to $13.16 in New York Stock Exchange composite trading. The stock has fallen 65 percent in the past year.

The case is Federal Trade Commission v. Whole Foods Market Inc., 07-1021, U.S. District Court, District of Columbia (Washington).

To contact the reporter on this story: Cary O’Reilly in Washington at caryoreilly@bloomberg.net.

Last Updated: January 13, 2009 16:44 EST