In a new strategy to rein in prescription drug costs, a group of 30 large employers has banded together to monitor the business practices of the middlemen drug buyers that most employers use to get discounts from pharmaceutical companies.

The new group, called Rx Collaborative, to be announced today, is part of a stepped-up effort by employers across the country to cope with drug costs that have been rising 11 percent or more annually. National spending on drugs rose to an estimated total of $199 billion last year.

The companies in the group - including Eastman Chemical, Mattel, Unocal and ING Americas - are using Medco Health Solutions, the largest of a small group of pharmacy benefit managers, or P.B.M.'s, that control 75 percent of drug purchasing by employers' health plans and insurers. Full Story...