The Federal Trade Commission said it would seek to block the proposed merger of Whole Foods Market Inc. and Wild Oats Markets Inc., charging that the deal would stymie competition in the organic groceries sector. The companies said they would fight an anti-trust lawsuit, claiming that the merger was necessary in what they said was a highly competitive market. Whole Foods announced in February plans to acquire Wild Oats. The FTC is seeking a temporary restraining order on the deal as the U.S. District Court in D.C. hears its request for a preliminary injunction. Whole Foods and Wild Oats argue that in considering their positions in the organic market, the FTC is missing the big picture the two chains account for only a tiny portion of the overall grocery category. According to the FTC, the Whole Foods and Wild Oats segment is separate from the grocery market and they cater to a distinct customer niche.