Wild Oats Markets Inc. and Whole Foods Market Inc. will go to court late next month in an attempt to keep the planned merger between the two companies alive.

The Federal Trade Commission has raised concerns about whether the two natural foods grocers should be allowed to merge. The two have agreed to a temporary restraining order, pending the July 31 hearing. The hearing is expected to conclude the next day.

The U.S. District Court for the District of Columbia will rule on whether to approve the FTC's request for an injunction to block the merger.

Austin, Texas-based Whole Foods (NASDAQ: WFMI) and Boulder, Colo.'s Wild Oats (NASDAQ: OATS) agreed in February to merge. Whole Foods offered $18.50 a share, plus taking over all of Wild Oats' debt.

Whole Foods has 195 stores, including two in New Mexico, and annual sales last year of $5.6 billion, while Wild Oats has 109 stores, including four in New Mexico, and $1.2 billion in sales.