PORTLAND – The president and chief executive officer of Mercy Hospital will step down before year’s end, just as preparations are being made to build a new medical center.

Howard Buckley, who has served 26 years as top executive, said the timing is right with construction looming.

“I’m at an age where sooner or later, someone’s going to walk in my office and say, ‘Howard, it’s time,”‘ Buckley said Wednesday. “I decided I want to go out according to my own drummer, not theirs.”

Buckley, 65, said he decided to retire about a year ago largely due to the hospital’s plans to move from its State Street location to a 40-acre site along the Fore River.

Construction likely will begin in late 2003 or early 2004 and will be finished within two years, he said. “It seemed appropriate to get somebody in here early on to take that process to completion,” Buckley said.

Buckley’s successor is expected to be named in August or September. On Thursday, the search committee will be listening to the results of interviews that were conducted by a search firm, hospital administrators said.

Since February, Tyler and Co. of Atlanta has steadily reduced the number of applicants from 150 to seven. The committee will next select three or four people for interviews.

During his tenure, Buckley often advocated for a single-payer universal health care system. He said his only major regret is leaving health care before that goal was achieved.

“I would’ve loved to see it,” said Buckley, who has served on various panels advocating for a single-payer system.

He said he is not sure if he will stay on as a member of the state’s Health Security Board, which is studying the feasibility of a single-payer system and will report its findings to the Legislature.

Don McDowell, former president and CEO of Mercy’s biggest rival, Maine Medical Center, described Buckley as a caring man.

“Having Howard in health care, in the state of Maine, in Portland, has been the best thing for the community,” said McDowell, who remained close friends with Buckley after Mercy pulled out of discussions in 1994 to merge with Maine Medical Center and the former Brighton Medical Center.

Before coming to Mercy, Buckley served as associate administrator of the Reading Hospital in Reading, Pa., from April 1972 to 1975 and at the Mount Sinai Medical Center in Milwaukee, Wisc., from 1967 to 1972.