Sister airlines United and Continental as well as American Airlines have announced a number of new services and incentives for customers flying between Chicago and California in response to discount flyer Virgin America’s newly launched service at O’Hare Airport.

United announced that it would start doubling award mileage promotion for its Mileage Plus members and United and Continental have added five daily round trips between O'Hare and San Francisco International Airport.

American Airlines also plans to add one round trip between O’Hare and Los Angeles from Thursdays to Sundays, bringing the airline up to a total of 11 daily round trips.

While service between Chicago and San Francisco and Chicago and Los Angeles is still dominated by United, Continental, and American, Virgin will be breaking into the O’Hare market with three daily round trips to San Francisco and two to Los Angeles.

According to Virgin America owner Richard Branson, "We've had to fight our way into Chicago".

While donning red boxing gloves on a tarmac at O’Hare, Branson claimed that it was the big airlines that had blocked Virgin’s previous attempts to enter the O’Hare market.

“This year, we gave them a really good left hand and we’re here to stay,” he said to a cheering crowd.