Southwest Airlines is raising its fares, again.

The Associated Press says the airline company is joining many other U.S. airlines in raising its fares, citing the need to offset high fuel prices. It's raising the price of many domestic round-trip airfares by $10.

Southwest's decision to raise its fares may have ensured success for a price hike by major airlines. Southwest has great influence over prices since it carries more U.S. Passengers that any other airline.

This marks the sixth time airlines have raised fares this year alone, meaning a ticket that would have cost $200 on Jan. 1 could now cost $260.

The Associated Press contributed to this story.