Catalyst Health Solutions, a Rockville firm that manages prescription drug benefits for companies and government agencies, was scooped up by Lisle, Ill.-based competitor SXC Health Solutions on Wednesday in a deal worth $4.4 billion.

If approved, the transaction will bring the two mid-size benefits managers under one corporate umbrella at a time when the industry is adjusting to new federal health-care mandates and handling more orders for lower-cost generic drugs.

The deal is expected to close in the second quarter pending regulatory and shareholder approval.

Catalyst shareholders will receive $28 in cash and 0.6606 shares of SXC stock for each share they hold, according to the firms, which implies a purchase price of $81.02 per Catalyst share. That’s a 28 percent premium over the firm’s closing price Tuesday.

Both boards of directors unanimously approved the deal.

The proposed acquisition follows the Federal Trade Commission’s approval this month of the merger between Express Scripts and Medco Health Solutions, two of the industries largest players.

“The combined company will be better positioned to compete against the larger players in the industry,” said David Blair, Catalyst’s chairman and chief executive. “We’ll have a full suite of products and services to offer those clients.”

Blair said that as a combined company, Catalyst and SXC will also be a more formidable competitor for contracts with large, national employers. That’s due in part to greater purchasing power that could drive down the cost of buying prescription drugs in bulk.

“We’ll be able to improve our cost position, which should generate savings for our clients,” Blair said.

Executives anticipate the combined company, which will be headquartered in Lisle, will generate $13 billion in revenue.

Catalyst has 1,500 employees nationwide, including several hundred in Maryland. Blair said it was too early to determine whether the merger would have an impact on those positions, but he confirmed that SXC will maintain a Rockville presence.

Catalyst’s share price jumped 34.1 percent in trading Wednesday, ending the day at $85.32. The announcement brought an 11.3 percent lift to shares of SXC, which ended the day at $88.63.