Amid speculation the San Diego Chargers may relocate outside San Diego county and talk of building a new football stadium in Mission Valley or downtown, one developer thinks the Chargers could build a home in South County.

Jeff Phair, owner of the Phair Company, said he and business partner Austin Dias have made a proposal to the owners of the Chargers in hopes of not only keeping the National Football League franchise in San Diego county but also bringing them to a portion of Chula Vista.

“We made a proposal to the Chargers two-months ago,” Phair said.

The proposal includes building a dual-use stadium in the South Bay that would house the Chargers and a Major League Soccer team. Phair dubs the project as the South County Chargers & Soccer Stadium Site.

Mark Fabiani, special counsel to the president of the San Diego Chargers, said in an email that he is aware of Phair’s proposal.

“At this point, we are focused solely on our work with the city of San Diego and the mayor’s newly-appointed task force. We are now waiting for the task forces’ decision on which site will be the focus of the task force’s site,” the email states. “We would encourage Mr. Phair to present his ideas to the task force if he wants to ensure that his site is among the sites that the task force is considering.”

Douglas Barnhart, a member of San Diego Mayor Kevin Faulconer’s stadium task force, said he has seen the Phair proposal but would not comment.

Phair said he envisions a 70,000 to 80,000- seat stadium along 100-acres of land between Main Street and Palm Avenue near Interstate-5.

But the land for the possible stadium isn’t completely secured yet.

Phair owns a portion of the land, while other parcels are owned by the city of San Diego, the city of Chula Vista, the county and private parties.

Chula Vista City Manager Gary Halbert said he has seen a letter drafted by Phair about an idea on how to resolve the Chargers issue and the potential of bringing an MLS team to Chula Vista.

“There certainly has not been any formal proposal to bring the Chargers to Chula Vista,” Halbert said. “If he (Phair) did make a proposal it was not made to the city, but to the mayor.”

Phair said he and a group of Mexican investors would put up $250 million to fund a dual-use stadium. He said the rest of the funding would most likely come from a joint powers agreement, which could provide bond financing.

A joint powers agreement means county residents would vote on whether or not to pass a bond, so financing would be shared by everyone in San Diego County instead of just the residents of the city of San Diego.

Phair said the NFL franchise rules state that an ownership group in one city must exhaust all viable stadium location options in the same city before consideration can be given to request to move to a different city.

Phair does not believe the Chargers have explored all their viable options.

“They’re only focused on Qualcomm and the stadium site downtown next to Petco Park,” he said. “But there have been other options that have been presented to them.”

“They had plenty of chances to look at it. I don’t think they really are trying to find a site here. They are looking for an excuse to go to Los Angeles.”

Phair said if an NFL stadium doesn’t materialize he’ll turn his attention to another brand of futbol.

“If the Chargers were to decline to look at my site, I’ll probably then switch my plan to building only a soccer stadium,” he said.

Mayor Mary Casillas Salas did not return phone calls seeking comment.