HealthNow New York President and CEO Alphonso O’Neil-White plans to retire and the Buffalo-based health insurer is planning to launch a national search to find his successor.

O’Neil-White, who has been HealthNow’s top executive for nearly a decade, did not say when he will retire or spell out a timetable for the search.

O’Neil-White, who is 64, said he is “initiating a transition plan” now to “allow for a seamless transition,” according to a company statement. The company did not name a successor, but O’Neil-White and Chairman Thomas J. Hook stressed that a succession plan is in place and the announcement allows the board “ample room to do a national search for O’Neil-White’s successor.”

O’Neil-White is not expected to step down until his successor is in place, said Julie Snyder, a HealthNow spokeswoman.

O’Neil-White, who has been CEO longer than any other recent executive in the company’s history, said he is in “excellent health.”

“This is an appropriate time for me to announce my intentions, not only because of my age and tenure, but because I know [HealthNow New York] is poised and prepared to thrive in the new health-care environment of the next several years,” he said.

O’Neil-White has been with the company for 17 years, since joining the company as senior vice president and general counsel and then taking a promotion to interim CEO in 2003. The company noted that he is credited with turning the company around, restoring it to a position of financial strength, higher and appropriate reserve levels and continued leadership of the market.

“I am extremely proud of what our company and team of leaders accomplished during this decade-long run I’ve so enjoyed,” O’Neil-White said.

O’Neil-White joined HealthNow in 1996 as senior vice president, general counsel and corporate secretary before being named interim CEO in December 2003 and permanent head in July 2004. Before his recruitment to HealthNow by former CEO Thomas Hartnett, O’Neil-White was vice president and general counsel for the national industry trade group now known as America’s Health Insurance Plans.

Previously, he served as labor counsel for Humana, a publicly traded national insurer specializing in Medicare, and general counsel for Group Health Association, one of the nation’s first HMOs. He began his career as an attorney in private practice, specializing in labor and management relations.

Besides HealthNow, he also serves on the boards of the Federal Reserve Bank of New York, the National Institute for Health Care Management, the Buffalo State College Council and the Albright-Knox Art Gallery.

The Buffalo-based company also stressed that “members, customers and associates will see no impact on services during the transition.”