In a deal estimated to affect more than 150,000 U.S. physicians and another 700 hospitals, Allscripts and Misys Healthcare have announced a merger.

The transaction, announced early Tuesday morning, gives British-based Misys Plc a 54.5 percent stake in the combined company, in which Raleigh, NC-based Misys Healthcare will be folded into a wholly owned subsidiary of Allscripts.

Allscripts, based in Chicago, provides clinical software, connectivity and information solutions for physicians.

"This agreement changes the landscape in healthcare information technology by creating a single company that will serve roughly 150,000 physicians with our portfolio of electronic health record, practice management and other software solutions," said Allscripts CEO Glen Tullman, who will lead the combined company. "Improving U.S. healthcare requires the ability to connect all stakeholders through the continuum of care, and today we have taken a major step towards doing that, with nearly one out of three physicians in America as customers of the combined company.

Misys Healthcare had been rumored to be on the market for some time. Following a failed attempt at a management buyout in late 2006, the company, which does considerable global business in the banking and treasury & capital industry, hired Mike Lawrie as its new CEO. Lawrie announced an ambitious three- to five-year plan to turn the sagging healthcare unit around, hired Vern Davenport as vice president and general manager of the healthcare unit in February of 2007, and sold off its diagnostic systems and computerized patient records businesses last August in an effort to focus of software for physicians' offices.