BURLINGAME, Calif. — Virgin America has so far avoided the cost of fulfilling its founder’s call for flight attendants to don killer new red shoes, though the US carrier’s net loss rose to $100.4 million last year.

Founder Richard Branson, whose Virgin Group holds a 25 percent voting stake, last year surprised Virgin America executives by unilaterally announcing that its cabin crew would kick off their black work shoes.

In their steps would come the new red patent high heels rolled out last year to counterparts at Virgin Atlantic Airways, footwear that the UK carrier’s chief executive said would add “even more glamor” to its uniformed staff.

Branson’s call at an event to launch Virgin America’s launch of services to Chicago last May was testament to his ability to generate publicity, but masked the challenges facing a carrier whose losses have grown to $460 million over the past four years.

A Virgin America spokeswoman said Saturday that there had been no movement on the shoes, a day after the release of full-year financial results that provided a mixed picture of its efforts to turn a profit for the first time.

The fastest-growing US airline vowed to move into surplus at the operating level this year, ahead of a potential initial public offering in 2013.

The closely-held carrier also moved into the official ranks of the US majors as annual revenue passed $1 billion for the first time since its 2007 launch.

Virgin America has grown to operate 51 planes with a strategy focused on low fares and innovative service that has commanded higher fares than discounters such as Spirit.

Its average passenger revenue rose 11.2 percent last year — above the industry average — despite the drag of new routes that typically require discounts to encourage business. Virgin America said mature routes operated since the final quarter of 2009 were profitable.

Cyrus Capital Partners, the US hedge fund manager, controls more than half of Virgin America, with management, employees and the Virgin Group holding the balance.