Medco Health Solutions Inc., the nation’s second-largest pharmacy benefit manager, has agreed to pay $155 million in fines to settle fraud and kickback claims brought by federal prosecutors in Philadelphia that stemmed from a pair of whistleblower cases filed in 1999 and 2000.

The settlement, which was struck after extensive mediations conducted by Senior U.S. District Judge J. William Ditter Jr., avoids a trial that would have lasted two months.