Topeka ? Kansas’ largest electric company volunteered Friday to reduce its carbon dioxide emissions, signing the first such agreement between a utility and the state.

The agreement between Westar Energy Inc. and the Kansas Department of Health and Environment doesn’t set specific emissions targets. But the utility committed itself to measuring greenhouse gases and looking for ways to lower them.

Westar expects to finish the first round of measuring CO2 emissions by October and to present a plan to the state for reducing them by April 2009, said Bill Eastman, who oversees its environmental programs. That plan could include capturing and storing CO2, he said.

The agreement is significant because the state never has regulated carbon dioxide emissions, which many scientists link to global warming. Legislators have rejected proposals this year to impose the state’s first CO2 limits.

Westar and the state struck their deal as legislators were trying to finish work on a bill allowing another utility to build two new coal-fired power plants in southwest Kansas, without any emission limits.

KDHE Secretary Rod Bremby blocked the southwest Kansas project in October over concerns about the plants’ potential CO2 emissions. He also promised to seek agreements like the one signed by Westar, arguing that the state can’t ignore the dangers of global warming.

“This agreement is a prime example of government and private industry working together to find common ground,” Bremby said in a statement.

Westar already planned to spend more than $750 million over five years to upgrade its power plants to control pollution that the state regulates, such as sulfur dioxide and nitrous oxide. Westar, with about 675,000 customers in eastern and central Kansas, has eight coal-fired units that generate about 79 percent of its electricity.

In disclosing the agreement, Bremby also announced he approved a construction permit for Westar’s planned upgrades to three coal-fired plants making up the Jeffrey Energy Center, about 30 miles northwest of Topeka. Jeffrey is the state’s largest coal-burning generating complex.

Westar announced last week that it would put off building any new coal-fired power plants as long as possible, citing “growing opposition” to coal as a major reason. The utility said the link between greenhouse gases and global warming had become a “mainstream belief” requiring “fundamental change” in energy production.

“We do customer surveys every year,” said Kelly Harrison, a Westar vice president. “Reliability is very important. Taking care of the environment is also very important to customers.”

Westar agreed to join The Climate Registry, a Boston nonprofit group developing a common method for tracking and reporting on greenhouse gas emissions. Thirty-nine American states, including Kansas, seven Canadian provinces and two Mexican states are members.

The utility agreed to reduce its net emissions of greenhouse gases under a plan to be approved by KDHE. If a step requires the utility to spend less than $1 million, it won’t seek a reimbursement of its costs through electric rates. If it spends more, it will have its rates reviewed by state utility regulators.

The five-page document was signed by Bremby and Doug Sterbenz, Westar’s executive vice president and chief operating officer.

Stephanie Cole, a spokeswoman for the Sierra Club, said Westar also appears to be preparing itself for potential federal CO2 regulations. Environmentalists have argued that Congress is likely to enact a program soon.

“It looks good,” Cole said of the Westar agreement. “We applaud their efforts all the way. Experts tell us federal carbon regulations are coming and Westar recognizes that and it’s good planning on their part.”

State legislators so far have resisted imposing CO2 limits on utilities, arguing that it would encourage businesses to leave Kansas. They’ve also criticized Bremby for his decision to deny an air-quality permit for the southwest Kansas project.

Hays-based Sunflower Electric Power Corp. proposes to build the two coal-fired plants outside Holcomb, in Finney County. The $3.6 billion project has bipartisan support among legislators.

They’ve said Bremby’s decision raises questions about whether he’ll renew operating permits for 16 existing coal-fired power plants, including the three at Jeffrey. All of them expire by September.

But Bremby has said he’s not planning to impose mandates on utilities or other industries and will rely on agreements such as the one with Westar.

“The initial information we have on this agreement indicates it is a good step in the right direction,” said Sebelius spokeswoman Nicole Corcoran. “It highlights how government and the private sector can successfully collaborate.”

Many legislators argue that the state needs new coal-fired plants to meet its future power needs. According to federal statistics, about 75 percent of the state’s electricity comes from such plants.

Sen. Jay Emler, a Lindsborg Republican helping to draft the final version of an energy bill, noted legislators expect to propose having a new commission study potential state-industry agreements on CO2. That proposal would be included with provisions giving Sunflower the go-ahead for its project.

As for Westar’s agreement influencing those discussions, he said, “I don’t think it will have any impact.”