Atlanta Gas Light customers — whose rates have been frozen for several years — can expect to pay more starting in 2010, parent company officials hinted Wednesday.

Executives of AGL Resources told analysts at a meeting in New York that the company will file a request with the state Public Service Commission in November 2009 to change rates the following year. If approved, the new rates would take effect in May.

Company spokesman John Kennedy said it's a long way off before AGL will decide whether that means monthly bills will go up or down, but he did say any requests "would be to reflect improved infrastructure and continued reliability for our customers."

An increase is almost certain, one expert said.

The price of steel and other building materials has gone up, causing many utilities nationwide to raise rates, said Paul Patterson, an energy analyst at Glenrock Associates LLC.

"There are increasing costs, and utilities are not immune to it," Patterson said.

Drew Evans, AGL's chief financial officer, told analysts that the company is "under pretty considerable pressure as it relates to costs."

But he said that no one should expect rates to go up in a "double-digit fashion."

"That's unacceptable to ratepayers and certainly unacceptable to regulators," Evans told analysts during a three-hour presentation.

The PSC froze AGL's rates through 2010 as part of a settlement with the company in 2005. As a result, the company was expected to forego about $2 million in revenue each year for five years.

However, regulators did not place a cap on the company's profits. The PSC usually requires utilities to share their profits once they reach a certain level.

Kennedy said that the settlement requires the company to update rates after the freeze ends.

Meanwhile, AGL is on schedule to start converting methane gas to natural gas at DeKalb County's Live Oak Landfill this fall, Kennedy said. The company is partnering with Jacoby Energy Development and Waste Management on the $25 million project that is expected to fuel 15,000 homes for the next 25 years.

"It's a 'green' concept to bring supply to the marketplace," said Hank Linginfelter, AGL's executive vice president for utility operations. "We believe this is an opportunity for us."