The Los Angeles County Board of Supervisors voted 4-0 today in support of transferring control of little-used Ontario International Airport, which is owned by Los Angeles World Airports, to the city of Ontario.

Supervisors Don Knabe and Michael Antonovich urged their colleagues to support the idea, saying that it presented an opportunity for the Ontario airport to attract more business and lessen traffic at LAX.

"The successful operation and growth of (Ontario International Airport) is a key component to regionalizing air service and providing a healthier, more sustainable transportation system within the Los Angeles region," read the supervisors' motion.  In April, negotiations over the valuation of Ontario broke down, with LAWA offering to sell the airport for $474 million roughly two years after Ontario offered to buy it for $250 million.

Ontario city officials responded by filing an administrative claim against LAWA, saying the offer was out of line with an existing joint-powers agreement between the two entities.

Shortly after the supervisors voted today, the Los Angeles City Council approved a multibillion-dollar makeover at LAX, including a runway realignment to widen a taxiway for a new generation of jumbo airliners.

Supporters of the modernization project at LAX say it is needed to keep the airport internationally competitive. LAX neighbors, however, have complained about traffic and noise associated with the region's No. 1 airport and threatened to sue the city.

A 2006 settlement agreement between LAWA, the county and several municipalities included a commitment by LAWA to support efforts to regionalize air traffic by developing airports such as Ontario.

But Ontario officials have criticized LAWA, saying it spends disproportionately on LAX.

Ontario has seen air traffic drop more than 40 percent since 2007, from about 7.2 million passengers at its peak to roughly 4.3 million passengers last year, resulting in a loss of more than $540 million and 10,100 jobs, according to an April report commissioned by supporters of local control.

"We have seen significant reductions in passenger traffic at Ontario, which cannot all be explained away by the economy," Knabe said. "LAWA has not shown a good faith effort to regionalization, which would benefit all of Southern California."

Airports in Burbank, Orange County, Long Beach and Palm Springs already operate under local control.

The board directed the county's chief executive officer to send letters to Mayor Antonio Villaraigosa and Ontario Mayor Paul Leon and LAWA, recommending the transfer of control. Supervisor Mark Ridley-Thomas abstained from voting.

In follow-up to a Feb. 26 discussion of the LAX expansion, the CEO is scheduled to present a report on airport regionalization at the board's May 14 meeting.