DALLAS (AP) -- Continental Airlines Inc. said Thursday it matched a move by other carriers to raise surcharges for travel on a few peak days in March and April to $30 each way.

The charges, tacked on to base fares, were already boosted from $20 each way by Delta, Northwest, United and American.

Surcharges range up to $50 for the day after the Super Bowl, while they remain $20 each way for certain days around the Thanksgiving and Christmas holidays.

The surcharges can differ by airline, but the $30 additional cost now applies on several of the largest carriers for travel on March 14, 20, 21 and 28 and April 5 and 11, according to Tom Parsons, CEO of travel web site Bestfares.com.

The extra charges started in September, and airlines have raised the amounts and applied them to more days -- about 40 between now and next May.

Earlier this week, US Airways started a separate 5 percent surcharge on all flights on or after next May 8. The airline said it made the move because fuel prices could increase by then.