Fri Mar 28, 2008 2:14pm EDT

CHICAGO (Reuters) – Northwest Airlines said on Friday it will begin charging $25 to check a passenger’s second bag, a move that other carriers have attempted to bolster revenue amid high fuel prices.

Coach class customers will not be charged to check one piece of luggage. Members of loyalty programs may still check two bags at no additional charge. Customers booked in first class can continue to check up to three bags at no charge.

Other changes include an increase from $80 to $100 for three or more checked bags, and an increase from $25 to $50 for overweight bags heavier than 50 pounds.

The new fees apply to flights within North America on or after May 5.

Northwest, the No. 5 U.S. carrier, is the fourth major airline to make the change. UAL Corp’s United Airlines, Delta Air Lines and US Airways Group Inc announced new fees earlier this year.

Airlines, grappling with soaring fuel costs, are looking for new revenue streams and cut costs.

One popular way to achieve these goals is by charging for items and services that used to be included in the fare. Airlines typically check two bags for free, but analysts forecast all the top carriers soon will begin charging to check a second bag.

Shares of Northwest fell 4.26 percent to $8.10 on the New York Stock Exchange early Friday afternoon.

(Reporting by Kyle Peterson, editing by Richard Chang)

For more information on flying, click here