SANTA ROSA -- Air Medical Group Holdings Inc., an air ambulance company that operates in 27 states, has signed an agreement to acquire REACH Medical Holdings LLC of Santa Rosa.

A REACH spokeswoman said the sale has not yet closed and didn't know when to expect it to be finalized. 

Air Medical will incur roughly $250 million in debt from the acquisition of REACH, according to a Moody's Investors Service report. The company operates through three subsidiaries -- Missouri-based Air Evac Lifeteam, Dallas-based Med-Trans Corporation and Kansas-based EagleMed. In 2010, Bain Capital acquired Air Medical from Brockway Moran & Partners and MVP Capital Partners for roughly $1 billion, according to Dow Jones News Service.

REACH, short for Redwood Empire Air Care Helicopter, was started in 1987 by the late John McDonald, a Santa Rosa Memorial Hospital emergency room physician. It currently is backed by Boston-based New Heritage Capital and operates a fleet of 17 helicopters and three planes out of 12 bases in Northern California, Oregon and Texas.

By comparison, Air Medical Group companies operate more than 200 helicopters and airplanes from 180 bases in 27 states. The company reported revenues of $441 million for the fiscal year ended June 30, according to Dow Jones, citing the Moody's report.

REACH employs more than 100 people in Northern California. Its local chief executive is Jim Adams.