* Air quality official has no-nonsense style
* Final decision not made (Updates with reaction, background)
By Jeff Mason
WASHINGTON, Feb 1 (Reuters) - President Barack Obama is leaning toward choosing Gina McCarthy, a top official in charge of air quality at the Environmental Protection Agency, to run the EPA in his second term, according to two sources familiar with the matter.
McCarthy, currently the assistant administrator for the EPA Office of Air and Radiation, would take on the top job as the agency leads Obama's push for measures to fight climate change.
McCarthy would replace Lisa Jackson, who said in December she planned to step down as EPA chief.
A final decision has not been made, and one source cautioned that Bob Perciasepe, Jackson's deputy, was still in the mix for the administrator post.
An announcement could still be a couple weeks away.
A Boston native, McCarthy came to Washington after serving as the top environmental regulator in Massachusetts and Connecticut under Democratic and Republican governors.
Former Massachusetts Governor Michael Dukakis, a Democrat, appointed her chair of a council to oversee a review of a proposed hazardous waste incinerator in the Boston area in 1990.
She later served as an environmental policy adviser to then-Massachusetts Governor Mitt Romney, and launched the state's first Climate Protection Action Plan. Romney was Obama's Republican opponent in the 2012 presidential election.
In 2004, McCarthy was appointed to head Connecticut's Department of Environmental Protection under then-Governor Jodi Rell, also a Republican, and helped lead the state into a carbon cap-and-trade system for Northeastern states, known as the Regional Greenhouse Gas Initiative.
Her no-nonsense style could be an asset in dealing with Congress if Obama embarks on ambitious new measures to tackle climate change, which he signaled in his inaugural address.
"She's about the most frank high-level public servant you've ever met," said one former colleague, speaking on condition of anonymity.
"She's a good manager, she picks stuff up fast, and she's ... certainly not afraid of a battle. So if they are anticipating a very combative Congress, Gina can certainly hold her own."
McCarthy would bring more gender equality to Obama's revamped Cabinet. The president has faced criticism for appointing white men to vacancies at the departments of state, defense and treasury.
Asked for reaction, a White House spokesman said he did not have any personnel announcements to make. (Additional reporting by Roberta Rampton and Valerie Volcovici, Editing by Alistair Bell and Peter Cooney)