Express Scripts Inc. (ESRX), working toward closing its planned purchase of health insurer WellPoint Inc.'s (WLP) in-house pharmacy benefits management, or PBM, operation, won't stop considering other potential acquisitions.

"We'll continue to look at opportunities at the right price and the right circumstances," David Myers, Express Scripts' vice president for investor relations, said Wednesday at the Thomas Weisel Partners Healthcare Conference.

The St. Louis pharmacy benefits manager, the third-largest in the market, will expand significantly once it completes its nearly $4.7 billion acquisition of WellPoint's NextRx subsidiaries. Express Scripts expects the deal to close in the fourth quarter.

After WellPoint and Express Scripts announced their transaction, which includes a 10-year contract for Express Scripts to provide services to WellPoint, the market turned its attention to the potential for other health insurers to divest their in-house PBMs.

Cigna Corp. (CI) has indicated an interest in placing its PBM for sale, and The Wall Street Journal reported that Aetna Inc. (AET) has put its drug-benefits business on the block.

Medco Health Solutions Inc. (MHS), one of the largest PBMs, is in a good position and will be opportunistic in terms of acquisitions, its chief executive said a few weeks ago. A spokeswoman for retail drug store-PBM hybrid CVS Caremark Corp. (CVS) said last week the company doesn't comment on rumors related to potential mergers and acquisitions.

Express Scripts shares recently rose 80 cents, or 1.1%, to $74.74.

-By Dinah Wisenberg Brin, Dow Jones Newswires; 215-656-8285; dinah.brin@dowjones.com