Key shareholder adviser backs Cigna-Express Scripts deal

Cigna's plan to buy pharmacy benefit manager Express Scripts for around $52 billion has received a big endorsement a few days after activist investor Carl Icahn urged shareholders to reject it.

The proxy advisory firm Institutional Shareholder Services said Friday that stock owners should vote for the deal later this month, calling it financially compelling.

Large institutional shareholders rely on ISS and similar firms to help them decide how to vote on certain company proposals.

Icahn had warned shareholders in an open letter that Cigna Corp. was paying too much for a company with a shaky future.

Pharmacy benefit managers like Express Scripts Holding Co. run prescription drug coverage for big employers and insurers, among other clients. They've become a focal point for criticism and regulatory scrutiny as drug prices rise.