HARRISBURG — The director of Gov. Ed Rendell's efforts to expand health insurance to low-income children and adults, help doctors pay their malpractice bills and modernize Pennsylvania's health care system is stepping down.

Rosemarie Greco will leave her post as director of the Office of Health Care Reform on Dec. 31, but will continue to advise the governor.

Pennsylvania has become a national leader on attacking hospital acquired infections and managing chronic diseases because of the work of Greco and her staff, Rendell said.

"What Rosemarie has accomplished, working with just a handful of staff over the past six years, is nothing short of amazing," Rendell said.

Greco, a former president of CoreStates Financial Corp. and chairwoman of the Greater Philadelphia Chamber of Commerce, has served with Rendell since 2003, when Rendell created the office to cut health care costs and ensure that more people had access to doctors and nurses.

One of Greco's first initiatives was a $220 million-a-year effort to help doctors pay for their medical malpractice premiums, although doctors accepting the help had to promise to continue practicing in Pennsylvania.

Later, she helped craft the "Cover All Kids" program that won legislative approval in 2006 to expand by thousands the number of uninsured children who get access to state-subsidized health insurance.

With Greco's help, Rendell also won passage of several laws in 2007 designed to lower the cost and improve quality and availability of health care.

Greco's deputy, Ann Torregrossa, will take her place.