REACH Medical Holdings, the Santa Rosa-based air ambulance service with operations in California, Oregon and Texas, is being sold to a subsidiary of Mitt Romney's old investment firm, Bain Capital.

Air Medical Holdings Inc., bought by Bain in 2010, is expected to incur $250 million in debt to help fund the purchase, according to a report by Dow Jones.

The transaction has received clearance from anti-trust authorities, according to a notice published this week on the Federal Trade Commission website.

A REACH official, Eric Freed, confirmed Friday that a deal was in the works but would not discuss details until it was final.

"It's not done at this point," said Freed, the company's director of service delivery. "We're in the middle of it."

Rumors of the sale have been swirling around the Charles M. Schulz-Sonoma County Airport, where REACH is based, said Doug Williams, chief of the Rincon Valley and Windsor fire departments. Some speculated that buyers with deep-pockets could invest in new equipment. Others worried the transfer of a family company to absentee owners would result in a loss of "local flavor."

"This is something that started here with people I personally knew," said Williams, a firefighter for 40 years. "It's certainly become an established part of the system."

REACH, which stands for Redwood Empire Air Care Helicopter, was founded in 1987 by Santa Rosa Memorial Hospital emergency room doctor John McDonald.

McDonald, who died in an airplane crash in 2000, wanted to extend emergency service to people living in remote areas of the North Coast.

Over 25 years, the company expanded to 12 bases in three states with 260 employees and reported revenue in 2008 of $40 million.

The company's chief executive is Jim Adams and McDonald's sons, Patrick and Dan, preside over the board of directors.

REACH provides air ambulance services to critically injured patients with a fleet of 17 rotor-wing aircraft and three fixed-wing planes.

The bright-red choppers are a common sight over Sonoma County, but they also fly above towns from Redding to Imperial County, and at bases in Corvallis, Ore. and Houston and San Antonio, Texas.

Sacramento-based CALSTAR is the company's Northern California competitor.

The buyer, Air Medical Holdings, is the largest independent provider of air ambulance services in the world, with 180 bases in 27 states and a fleet of more than 200 helicopters and planes.

It currently operates through three subsidiaries: Air Evac Lifeteam, in West Plains, Mo.; Med-Trans Corporation, in Dallas; and EagleMed, in Wichita, Kan.

The company reported revenue of $441 million in the 12 months ending June 30, according to Dow Jones, which cited a report by Moody's Investors Services.

Bain acquired Air Medical Group Holdings in 2010 from Brockway Moran & Partners and MVP Capital Partners for about $1 billion, according to the Dow Jones report.

"Air ambulances play a vital role in the rural health care infrastructure since many Americans live more than a one hour drive away from acute medical care," John Connaughton, a Bain managing director, said in 2010. "We are greatly impressed by the quality of Air Medical Group's management team, industry leadership position and track record of delivering high quality, innovative and cost effective health care."