WASHINGTON – A merger creating the nation’s largest managed care provider received approval from federal regulators Friday.

The Justice Department declined to block the multibillion-dollar deal between Anthem Inc. and WellPoint Health Networks Inc. on antitrust grounds. The cash and stock deal was valued at $14.3 billion when it was announced last October.

Under the proposed merger, the slightly smaller Anthem would acquire WellPoint of Thousand Oaks, Calif. The combined entity would keep the larger company’s name but consolidate operations in Indianapolis, where Anthem has its headquarters.

Leonard Schaeffer, chairman and chief executive of WellPoint, has said the merged company hopes to “redefine the industry” with new products that offer their members more choices, better services including information, and simpler transactions.

Consumer groups have expressed concern about allowing the nation’s two largest Blue Cross Blue Shield providers to merge.

“There’s a concern of loss of choice within a given market,” said Bob Hunter, director of insurance at the Consumer Federation of America. “Sometimes the impact can be minor and sometimes it can be severe. The bigger the companies that are merging, the more likely you’re going to have several states with severe problems of loss of choice and access.”

In Maine, Anthem spokesman Bill Cohen said Friday afternoon that since Wellpoint doesn’t have a presence here, the acquisition will have no impact. “All health care is local; it’s all governed at the state level,” Cohen said.

Joe Ditre, executive director of Maine Consumers for Affordable Healthcare, said he had little reason to think the merger would improve Anthem’s performance in Maine. “How much bigger does the 800-pound gorilla have to get?” he asked. “Anthem had $5 billion in assets when it came to Maine [and purchased the state’s nonprofit Blue Cross and Blue Shield programs].”

Now despite all the assets the company will have after the $14.3 billion merger, Ditre said, there will be no cost savings to the people of Maine.

“All they’ve done is channel money to Wall Street,” he said.

Also on Friday, Anthem released notification of its inclusion for the third consecutive year in Fortune magazine’s list of the “ten most admired health care companies in America.”

Anthem owns Blue plans in nine states: Colorado, Connecticut, Indiana, Kentucky, Maine, New Hampshire, Nevada, Ohio, and Virginia. WellPoint operates Blue plans in California, Georgia and Missouri, and recently won approval to acquire Wisconsin’s plan.