The name says ipayOne, but the Carlsbad real estate company that bought the naming rights to San Diego's Sports Arena two years ago is not paying any longer, the arena's operator said Friday.

IpayOne is in default on its $2.5 million naming rights agreement, said Ernie Hahn II, who heads Arena Group 2000. The group has a lease with the city of San Diego to manage the Point Loma arena until 2017.

Hahn said that ipayOne made initial installments on the $2.5 million it agreed to pay over five years, but then it stopped. "We've had to send letters, reminders," he said. "It's been less than ideal."

IpayOne, with offices on Palomar Airport Road, is a real estate brokerage and mortgage company that challenged conventional 6 percent real estate commissions by charging as little as 1 percent for selling homes.

On Friday, it had only one notice on its Web site - saying that it would no longer accept new listings and asked buyers and mortgage customers to make contact by e-mail. It was signed by Michael Jackman, the company's chief executive officer. Jackman did not return calls for comments.

Hahn said that his group was looking for a new naming sponsor. The 40-year-old arena, once home to professional basketball soccer and hockey teams, now serves as a venue for various shows, such as Disney on Ice and concerts, as well as the site of the weekly Kobey's Swap Meet. However, many large concerts now play at Cox Arena at San Diego State University or Coors Amphitheatre in Chula Vista.

Hahn said that ipayOne was supposed to pay $500,000 annually, but that amount had been scaled lower during the first two years because the company was a startup. The city of San Diego was to receive $250,000 of the $2.5 million in the first five years, then $50,000 on each annual $500,000 payment thereafter.

Hahn said that his father, Ron Hahn, who is son of the late real estate magnate Ernest Hahn, invested in ipayOne after the company got the naming rights. "He liked the model," Ernie Hahn said, but added that he hadn't talked about the company's finances with his father: "We don't get together over tea to discuss investments."

- Contact Business Editor Ann Perry at (760) 740-5444 or aperry@nctimes.com.