Mercy, Jeff link creates a giant. (Mercy Health Corp. and Jefferson Health System Inc. to form largest health network in Philadelphia)

Mercy Health Corp. and Jefferson Health System have agreed to join forces to create the largest health network in the Philadelphia region, bringing together hospitals, physician practices, home health agencies and managed-care products with combined annual revenues of more than $1.5 billion.

Although few details have been finalized, the combination will not involve a merger of assets or debt, but will instead create an "alliance" between the two organizations. The partners will form a new operating company with governance and oversight provided by a joint board of directors with "balanced" representation of Mercy and Jefferson officials, said Douglas S. Peters, president and chief executive officer of Jefferson Health System.

Mercy and Jefferson expect to reach a definitive agreement on the structure of the alliance by April 30.

The partners plan to entice additional hospital members who would, in turn, have representation on the governing board.

Although no assets will be exchanged, Jefferson and Mercy …