Grand Circle Corporation says it is offering 2010 trips with the guarantee that if a solo traveler finds a comparable trip at a lower price, the company will match it and take an additional $500 off the cost.

Grand Circle owns Overseas Adventure Travel and Grand Circle Travel, which serve the American 50-plus market. The company says it has the industry’s best values for solo travelers, who often have been penalized.

Grand Circle has eliminated or lowered the so-called “single supplment” fees on most of its trip and launched other programs to attract solo travelers, the majority of whom are women.

The company said solo women travelers represented just 10 percent of its business five years ago, but that percentage now has risen to 25 percent.

Grand Circle offers land vacations, river cruises and small ship adventures. For a 2010 catalog, call 1-800-873-5628 or visit oattravel.com/guarantee or gct.com/guarantee.