Whole Foods Market Inc., the largest U.S. natural-foods grocery chain, shares rose the most in a week in New York trading after a federal appeals court rejected the government's attempt to stop its acquisition of Wild Oats Markets Inc.

Whole Foods shares rose $1.20, or 2.7 percent, to $44.54 at 4 p.m. in composite trading on the New York Stock Exchange. Wild Oats, based in Boulder, Colo., increased 39 cents, or 2.2 percent, to $18.46.

Paul L. Friedman, a U.S. district judge in Washington, last week turned down the Federal Trade Commission's bid to stop the $565 million purchase. The FTC had contended that the purchase would limit competition and lead to increased prices. The appeals court Thursday denied the government's request that the decision be put on hold.

The denial of the emergency stay allows the companies to complete the transaction, said Clifford Aronson, a Skadden, Arps, Slate, Meagher & Flom lawyer who represents Wild Oats.

FTC spokeswoman Claudia Bourne-Farrell said Friday that the agency was "reviewing its options." She declined to give any details.

Whole Foods, based in Austin, Texas, agreed to buy Wild Oats in February for $18.50 a share. The FTC sued to block the transaction in June.