Genpact Ltd (NYSE: G), the outsourcing company spun off from General Electric Co., has agreed to acquire privately-held IT services provider Headstrong Corp. for $550 million in cash to expand its operations in the United States.

Bermuda-based Genpact said it expects the transaction to add to its earnings per share on a GAAP basis in 2011. Genpact also expects Headstrong’s long-term growth rate to be in excess of 20 percent per year.

The acquisition of Headstrong will also help us expand operations in the U.S. and shift our center of gravity to be even closer to our clients, said Genpact’s Chief Operating Officer Tiger Tyagarajan.

The newly-expanded company will be able to meet the growing needs of companies in the capital markets, financial services and healthcare verticals for governance, risk, compliance and back-office processing services, Genpact said.

Fairfax, Virginia-based Headstrong, with revenue of around $217 million in 2010, is focused in the capital markets and securities industry space. It counts nine of the world’s top ten investment banks and three of the top five asset managers as clients.

Headstrong has about 3,700 employees globally and generates a significant amount of revenue from employees who are onsite with clients in the United States, the United Kingdom and Japan.

The deal is expected to close by May 31.

Shares of Genpact closed Tuesday's regular trading 1.7 percent higher at $14.76 on the NYSE.