Ford Motor matched General Motors yesterday in offering all buyers the same discounts to employees after the incentives helped GM record its best sales month in 18 years in June.

The program, called the “Ford Family Plan,” will begin tomorrow and apply to 2005 Ford, Lincoln, and Mercury models, spokesman David Reuter said. Earlier yesterday, GM said that its plan, which sparked a 47% increase in June domestic sales, will be extended to August 1. DaimlerChrysler’s Chrysler division begins its version of GM’s program today.

“GM is forcing the others to roll it out, and it just stresses the competitive pressures that have been brought to bear in the market,” said Wil Stith, a portfolio manager at MTB Investment Advisors in Baltimore, who helps manage about $2 billion in fixed-income assets including Ford and GM debt. “The gains could be fleeting, but it was a good ploy from GM.”

GM and Ford, the two biggest American automakers, have tried several new programs this year to reverse market-share losses to competitors such as Toyota Motor and Nissan Motor. Ford has lost domestic market share for 28 straight months, and declining sales prompted Ford to twice lower its earnings forecast this year, most recently on June 21. Ford’s first quarter profit fell 38%.

The company now expects full-year profit, excluding some one-time costs, of $1 to $1.25 a share compared with a forecast of $1.75 to $1.95 in January. Ford, of Dearborn, Mich., doesn’t make forecasts for net income. On May 5, Standard & Poor’s cut its ratings on Ford debt to junk status, BB+.

Toyota, Nissan, and Honda spokesmen said yesterday the Japanese-based companies wouldn’t match the American automakers’ plans. Asian automakers’ American market share fell in June for the first time since August 2004.

Under the Ford plan, customers will be offered reduced prices and cash rebates. For example, the XLT version of the Ford Escape SUV will have a discounted price of $23,335 compared with the normal $26,070, Mr. Reuter said. Customers will be offered an additional $2,000 off – putting their final cost at $21,335, he said.

Dealers were being told yesterday of the plan’s details, and advertisements will begin today, Mr. Reuter said. The program doesn’t apply to Ford Mustang and GT cars and the hybrid gasoline electric Escape SUV, he said. Ford’s Volvo, Jaguar, Land Rover, and Aston Martin brands also aren’t covered.

GM’s June employee-discount offer helped lift domestic industry sales for the month to an annual rate of about 17.5 million cars and trucks, from 15.4 million in June 2004 and 16.7 million in May, according to Autodata of Woodcliff Lake, N.J.

Ford’s sales in June rose 0.7%. Its American market share fell to 17.2% from 19.8% a year earlier. In 2000, Ford claimed 24% of American sales.

“No war transpires without bloodshed,” said Sasha Kamper, who helps manage $86 billion in debt at Principal Global Investors in Des Moines, Iowa, including GM and Ford bonds. “For those companies competing solely on price, future margins are the likely casualties.”

GM began offering all buyers the same discount it gives to employees on June 1 after its American sales through May fell 6.7% and inventories of unsold vehicles climbed while GM cut production. Detroit-based GM had a first-quarter loss of $1.1 billion, and its U.S. market share had fallen to an 80-year low while Toyota and other Asian rivals posted market-share records.

“It’s like ‘Keep America Rolling’ was in ’01 – let’s keep it going as long as it works,” Argus Research analyst Kevin Tynan in New York said. “Keep America Rolling” was GM’s initial offer of no-interest financing made shortly after the September 11 terrorist attacks.

The discount, which was to expire yesterday, helped lift GM’s June sales to 558,092 vehicles, 47% above a year earlier and the highest for any month since September 1986.