COTATI — ProTransport-1 ambulance and medical transportation service on Wednesday said it reached an agreement to merge with PRN, a major Southern California ambulance service.

While PRN is already one of the largest private ambulance services in Los Angeles with many prominent hospital clients, its merger with ProTransport-1 will bring ambulance industry expertise as well as capital to the company to help fuel its growth, according to Cotati-based ProTransport-1. Completion of the deal is pending regulatory approval.

PRN Ambulance will continue as the trade name and licensed ambulance provider in Southern California. PRN owner and President Avo Avetisiyan will stay in that role and become a member of the ProTransport-1 leadership group.

PRN and ProTransport-1 focus on providing ambulance services to patients transferred between hospitals. Together they will operate 225 ambulances in California. ProTransport-1, with operations throughout the Bay Area, Sacramento and the Central Valley, was recently honored as one of Inc. Magazine’s 5,000 Fastest Growing Companies in America for the fourth consecutive year.

New Heritage Capital, a Boston-based private equity group, partnered with and invested in ProTransport-1 in 2012. Heritage has made a name for itself by partnering with entrepreneurs, many of them in the healthcare field, to take their businesses to the next level.

PRN Ambulance was started in October 2010 and has quickly grown to become a significant provider of essential medical transportation in all of Los Angeles and Orange counties. Started with just three ambulances by, the company now operates nearly 60 emergency-response vehicles with well more than 200 employees.

Elena Whorton and Mike Sechrist started ProTransport-1 (protransport-1.com) started in 2000, taking a "patient advocate" approach to medical transportation industry. The company ranked No. 4,952 in its fourth consecutive time on the Inc. 5000 list of fast-growing U.S. companies, with 44 percent revenue growth to $48.5 million last year from $33.7 million three years before. The company bolstered its workforce to 747 last year, adding 403 in three years.