LOS ANGELES – The federal government socked Continental Airlines Inc. with a big fine Thursday for advertising ticket prices without clearly disclosing hefty fuel surcharges that could almost double the fare.

The U.S. Department of Transportation issued a civil penalty of $120,000 against Continental, and also announced a $45,000 fine against US Airways Group Inc. for a similar violation.

In the case of Continental, federal investigators found the airline’s website offered tickets that did not include fuel surcharges. For example, the airline was selling flights from San Jose to San Salvador for $298. But when passengers began to book the seat, they found that the actual price was $538 with fuel charges, according to the DOT.

A Continental spokeswoman said the violation was the result of a computer programming glitch. “We immediately responded to the Department of Transportation’s concerns and addressed the issue,” said Julie King.

Including the fines announced Thursday, the DOT has issued eight penalties against airlines and travel agencies for failing to disclose full prices, totaling $389,000 in fines, according to agency records.

In many of the past penalties issued against airlines, the agency found that the air carriers failed to note — using an asterisk or a website link — that the advertised fares did not include taxes and fees. Those fines usually ranged between $20,000 and $60,000 per violation.

In the case of US Airways, the DOT found that the airline advertised flights from the U.S. to Rome for $659 this year. Although the air carrier noted with an asterisk that the final price might include taxes and fees, the airline’s website and ads did not spell out those extra costs, according to the agency.

The airline told the DOT that the mistake was inadvertent and was fixed within 24 hours.

Last year, the agency issued 18 fines for violations of the law, for a total of $542,500 in civil penalties.

The largest fine was $200,000 against Unique Vacations Inc. of Miami, for offering a vacation package that the company said included “free airfare.” A DOT investigation found that customers who bought the package had to pay for some “airline costs,” including fuel surcharges.