By Jon Kamp SXC Health Solutions Corp.'s (SXCI) acquisition of fellow pharmacy-benefit manager Catalyst Health Solutions hasn't hampered the company's ability to compete for business, SXC Chief Executive Mark Thierer said. Mergers between pharmacy-benefit managers, known as PBMs, can sometimes prove disruptive for the health plans and companies that hire them to manage drug benefits. Though SXC and Catalyst closed their deal just last week, Mr. Thierer said he anticipates the newly combined company will continue to win new business. "I'm actually wildly optimistic" about the current selling season for 2013, which runs until early autumn, the CEO said in an interview. The company is rolling out a new name Tuesday--Catamaran Corp.--and will start trading Wednesday under the ticker symbol CTRX. "We've already had some wins," Mr. Thierer added, such as a three-year contract with Blue Cross & Blue Shield of Rhode Island disclosed in February. "Business is moving." He said there has been a much higher-than-normal level of PBM clients putting out requests for proposals, a trend also highlighted recently by other industry executives and consultants. While all these requests don't automatically mean clients will change hands--some may be testing the waters, but could re-sign with their current benefit manager, consultants have said--Mr. Thierer said he sees opportunity in the commotion. He chalked up the busy selling season to a handful of factors that have caused PBM clients to survey their options, including the fractured relationship between big PBM Express Scripts Holding Co. (ESRX) and drugstore Walgreen Co. (WAG). Express Scripts is also coming off a large transaction--in April it closed on its purchase of Medco Health Solutions to create the industry's largest company. "The big dislocations happening in the industry right now have driven so many opportunities," Mr. Thierer said. Both SXC and Catalyst have pipelines of new business activity--meaning requests to which they are responding that could turn into new business--that are two or three times bigger than what either company has ever seen before, he added. He agreed that mergers usually slow down sales activity at PBMs, but said "that is absolutely not the case" following the Catalyst deal. SXC became the fourth-largest PBM by prescription volume through the deal, ranking behind Express Scripts, CVS Caremark Corp. (CVS) and a unit of UnitedHealth Group Inc. (UNH). SXC plans to use its newfound heft to compete more for the biggest corporate PBM customers, which have traditionally gravitated toward Medco and CVS Caremark. One big question for the newly minted "Catamaran" is whether it will be able to keep an important customer--the insurer HealthSpring, which Cigna Corp. (CI) bought early this year--when a contract ends after 2013. Cigna hasn't disclosed plans for that contract, though it has said all options are on the table for its own internal PBM business. Barclays analyst Lawrence Marsh said he believes SXC can grow its business with Cigna, rather than losing out, should Cigna choose to outsource PBM operations. Mr. Thierer said he won't project what could happen but noted his company is spending a lot of time talking to Cigna about the possibilities. "We view our opportunity to expand our relationship with Cigna as an important one," he said. SXC shares were up 0.4% to $95.34 in recent trading, and have risen about 69% this year. Write to Jon Kamp at email@example.com.