PORTLAND — The University of Southern Maine is accepting applications for a new nursing practice doctoral program that’s starting next fall.

The program will be the first of its kind in northern New England at a time when a doctorate of nursing practice is becoming an increasingly popular and sought after credential, said USM spokesman Robert Caswell.

University of Maine System trustees approved the program in September.

The number of U.S. students enrolled in nursing practice doctoral programs increased from 3,415 in 2008 to 5,165 in 2009, according to the American Association of Colleges of Nursing.

The number of nursing practice doctoral programs has increased from 17 in 2006 to 120 today. Another 161 institutions are considering or planning similar programs.

A doctorate of nursing practice is expected to be a required credential for all advanced practice nurses by 2015, according to a nursing college association policy.

A doctorate of nursing practice provides advanced leadership and management skills needed as a part of day-to-day operations in healthcare delivery, unlike a doctorate of nursing, which trains students for careers in research.

USM’s nursing program is the largest in Maine, with 441 undergraduate students and 120 master’s degree students.