The Encounter restaurant atop the iconic Theme Building at Los Angeles International Airport closed permanently at the end of December, leaving airport officials seeking a new operator.

Delaware North had operated the restaurant since 1997 but chose not to extend its agreement to continue running it, airport spokeswoman Nancy Castles said.

”Delaware North Corporation, operator of the Encounter Restaurant, notified us several weeks ago that they decided not to continue operation of the restaurant,” Castles said in an email. “We are discussing operating concepts and options with several other concessionaires.”

The Theme Building in the center of the airport terminals was built in 1961 and is perhaps the most recognizable part of LAX. It was seismically retrofitted in 2010 at a cost of $12.3 million, but is essentially unchanged from when it was built.

While the building is an L.A. icon, there is not much historical significance to the Encounter restaurant, which was one of a series of concepts that has occupied the space in the past five decades. The Encounter opened to much fanfare in 1997 with a futuristic interior designed by Walt Disney Imagineering. But the restaurant had not been updated and it appeared dated in recent years.

Whatever company takes over the space will likely renovate it and change its name. But in a brief telephone interview, Castles said the outside look of the Theme Building will not change.

“The retention of the exterior look was a priority during (Los Angeles World Airports’) renovation and seismic retrofit in 2010,” Castles said. “Whatever new food and beverage concept is built out in the restaurant is not expected to have an effect on the exterior of the building.”

The observation deck above the restaurant remains accessible. It is open from 8 a.m. to 5 p.m. on Saturdays and Sundays. There is no charge to visit the deck.