PRN Ambulance in North Hills announced Wednesday it has reached an agreement to merge with Pro Transport-1, a major ambulance operator in Northern California. PRN, which has nearly 60 ambulances in the Los Angeles and Orange County markets, will continue with its trade name and leadership under President Avo Avetisiyan. Financial details of the transaction were not disclosed. Both companies specialize in transporting patients between hospitals or other care facilities. Together, they will have about 225 ambulances. Pro-Transport covers the San Francisco Bay area, Sacramento and the Central Valley. It is based in the Sonoma County city of Cotati. The merger will “bring ambulance industry expertise to further scale, as well as capital, to the company to help fuel its growth,” PRN said in a statement. New Heritage Capital, a Boston private equity firm, took a stake in ProTransport-1 in 2012 with the goal of expanding the company.