WASHINGTON — The U.S. Justice Department yesterday approved Whirlpool Corp.'s purchase of Maytag Corp. for $1.68 billion in cash and stock, saying the deal would not reduce competition substantially.

Benton Harbor, Mich.-based Whirlpool finally got the green light after weeks of speculation that regulators might file a lawsuit to stop the deal on antitrust grounds. The deal went through only after Justice Department officials took an "exhaustive look" at concerns about its market-share implications.

The acquisition, approved without any required divestitures, will create the world's largest appliance maker, accounting for 70 percent of U.S. sales. Thomas O. Barnett, the Bush administration's antitrust chief, said "competitive dynamics" will deny the new company power to raise prices.

"I'm stunned," said Mirko Mikelic, a senior portfolio analyst with Fifth Third Bank in Grand Rapids, Mich., which has $21 billion in assets, including Whirlpool bonds. "I thought they would need to do at least something to appease the Justice Department."

Investors welcomed the news. Shares of Maytag surged $4.73, or almost 28 percent, to $21.81 on the New York Stock Exchange. Whirlpool rose $6.38, or 7.1 percent, to $95.95.

Whirlpool Chief Executive Officer Jeff Fettig said he expects to complete the deal by April 3 and conceded he felt some nervousness about winning over the Justice Department. For Whirlpool, it means acquiring such Maytag brands as Hoover, Jenn-Air and Magic Chef.

Government lawyers who investigated the deal had raised concerns it would lead to higher prices for washing machines because of the dominance in the U.S. of Whirlpool and Maytag, said lawyers familiar with the matter who spoke this month on condition of anonymity because they weren't authorized to discuss the transaction.

Barnett told reporters that cost savings from the combination and increased competition from foreign manufacturers "rebutted that presumption" that a company with 70 percent of the U.S. market could stifle competition.

Whirlpool argued that growing foreign competition from makers such as China-based Haier Group Corp., LG Corp. of South Korea and Sweden's Electrolux AB would constrain its ability to raise prices.