Cigna shareholders are backing the insurer's planned takeover of pharmacy benefit manager Express Scripts, a deal that activist investor Carl Icahn had urged them to reject earlier this month.

Cigna says about 90 percent of votes cast on Friday were in favor of the roughly $52-billion deal, which also received broad approval from Express Scripts shareholders.

Icahn had warned shareholders in an open letter that Cigna Corp. was paying too much for St. Louis-based Express Scripts Holding Co. But other shareholders and the proxy advisory firm Institutional Shareholder Services backed the acquisition plan, which was announced earlier this year.

The deal still needs regulatory approval. Bloomfield, Connecticut-based Cigna expects to close it by the end of the year.

Shares of both companies advanced slightly with broader markets in midday trading.