Shares of Envision Healthcare Holdings Inc , owner of the largest U.S. ambulance service, rose 10 percent in their market debut, valuing the company at $4.24 billion.

Envision, formerly known as Emergency Medical Services Corp, priced its initial public offering of 42 million shares at $23 per share - at the high end of the expected range of $20 to $23.

Apart from medical transportation, the Greenwood Village, Colorado company also has a presence in hospital/inpatient care, radiology surgery and tele-medicine.

Envision shares were at $25.14 in early trading on the New York Stock Exchange.

(Reporting by Neha Dimri and Zeba Siddiqui in Bangalore; Editing by Maju Samuel)