American Express Co. is beefing up its marketing efforts on campus, offering travel bargains and launching a magazine for college students who carry the American Express Card.

Researchers say there are about 7 million fill-time college students in the United States spending an estimated $44 billion a year.Students also have the potential for substantial earnings growth once they graduate, and financial service companies are finding that it can often pay off to establish a relationship while they are still in college.

The market research company CollegeTrak said 51 percent of college students already have one of the major credit or charge cards.

Citibank, the nation's largest banking company which has also courted the college crowd, counts 1.3 million college students as holders of either its Visa or MasterCard credit cards.

American Express said the number of college students holding its payments card has doubled to more than 500,000 in the past two years, partly because of relaxed eligibility requirements.

Full-time college students can get an American Express Card without meeting any minimum income requirement and without a parent as co-signer, provided they do not have a bad credit record. The annual fee is $55, the same as for regular cardholders, and payment in full is due every month.

Despite the relaxed eligibility requirements, people who got the American Express in college "were just as responsible about credit" as other new cardholders, according to Ken Chenault, general manager of American Express' personal card division.

American Express also plans to publish a quarterly lifestyle magazine, American Express Connections, that will be sent to its college student cardholders. The magazine will offer tips on travel and money management, stories about campus theater and the professions and mail-order clothing, electronics, entertainment and travel.

American Express officials declined to specify how much it was spending on the program but said it was a multimillion dollar effort.