DETROIT — Less than two years after entering bankruptcy, General Motors will extend millions of dollars in bonuses to most of its 48,000 hourly workers as a reward for the company’s rapid turnaround after it was rescued by the government.

The payments, disclosed Monday in company documents, are similar to bonuses announced last week for white-collar employees. The bonuses to 76,000 American workers will probably total more than $400 million – an amount that suggests executives have increasing confidence in the automaker’s comeback.

In the four years leading up to its 2009 bankruptcy, GM piled up more than $80 billion in losses and was burdened by enormous debt and costly labor contracts.

“On the whole, we made tremendous progress last year,” CEO and Chairman Dan Akerson said Monday in an e-mail message to employees announcing the payments. “With our collective teamwork, this can be just the beginning.”

The company made $4.2 billion in the first nine months of 2010 and is expected to announce a fourth-quarter profit soon.

Most of GM’s hourly workers will get a record payment of more than $4,000 – more than double the previous record in 1999, at the height of the boom in sport utility vehicles and pickup trucks. Nearly all 28,000 white-collar workers such as engineers and managers will get 4 to 16 percent of their base pay. A few – less than 1 percent – will get 50 percent or more.

Bill Selesky, an auto industry analyst with Argus Research in New York, called the recovery “dramatic” and said the payments were needed to stop talent from jumping to other automakers, especially rival Ford.

The company, he added, is also trying to send a message: “It’s the new GM.”

But the bonuses drew criticism from an opponent of the auto industry bailout in Washington who said GM should repay its entire $49.5 billion loan before offering bonuses.

“Since the taxpayers helped these companies out of bankruptcy, the taxpayers should be repaid before bonuses go out,” said Republican Sen. Charles Grassley of Iowa. “It sends a message that those in charge take shareholders, in this case the taxpayers, for a sucker.”

The government has been repaid $23 billion but needs $26.4 billion more to recoup its whole investment. The government still owns 500 million shares of GM common stock, which would have to sell for roughly $53 per share to get all the money back.

Joe Ashton, the United Auto Workers vice president dealing with GM, joined a GM labor relations executive in signing a message to workers saying that the payments are a good example of how union members are sharing in the company’s success.

“We know that 2011 is an important year for both the UAW and GM with contract talks approaching,” the message said. “We look forward to getting a contract that is beneficial to both employees and the company.”

The payments follow GM’s surprising return to profitability last year.

The company emerged from bankruptcy cleansed of most of its debt and burdensome contracts and has shown it can make money even in a depressed auto market. Consumers bought only 11.6 million cars and trucks in the United States last year, far below the peak of 17 million in the middle of the last decade.