Faced with a booming federal business, Centel Information Systems Inc. of Rockville has split into two units that will handle its commercial and federal contracts separately.

One unit, Centel Federal Systems, handles all federal government business and is headed by Peter P. Kusek, former executive vice president of Centel Information Systems.

The other, Centel Information Systems, handles all commercial business. Carl English remains as president.

"This is a recognition by Centel of a commitment to the federal government marketplace and an increased focus on that marketplace by establishing a separate team," Kusek said. Both units will continue to be based in Rockville.

In the past year, the computer systems integrator, a division of Chicago-based Centel Corp., has seen orders with the federal government double, so officials decided to follow an industrywide trend and set up an operating unit solely for servicing government customers.

"We've had a lot of success over the past year and a half in terms of growing both the federal business and the commercial business," Kusek said.

Company officials expect continued strong growth this year.

Kusek said the federal government is no longer buying personal computers off the shelf from government-approved computer stores.

The government now has more sophisticated and complex requirements and is looking for integrated network systems that can provide a range of capabilities for their users.

In 1987, the company's revenue from the federal division was about $50 million, more than half of its total annual revenue of $85 million, said Kusek.

The federal systems division provides services to the Internal Revenue Service, the Department of Defense, NASA, the Department of Labor and others.

Centel provides sophisticated computer workstations equipped with Tempest, a technology designed to prevent electronic eavesdropping, to one federal agency. Kusek said contract provisions did not allow him to name the agency.

Last year, the company won a $100 million, three-year contract to provide the U.S. Postal Service with a nationwide computer system to process change-of-address mail.

Centel's Federal Systems division employs 300 people in Rockville and at three other sites.

Kusek said he expects to add 90 to 100 employees in his division in 1988.

Centel Information Systems, the commercial operating unit of the company, continues to handle private-sector customers. It provides PC-based systems to Fortune 1000 companies and will distribute computer products through IBM product centers that it plans to open nationwide.

Revenue for the commercial division last year was about $35 million, Kusek said. The division employs about 350 people, and officials expect to add 70 employees in 1988, according to Kusek.

Commercial clients include Westinghouse Electric Corp., Mack Trucks Inc., and Chrysler Corp. Last year, the commercial division was awarded a $25 million contract to install and maintain PC systems at 4,000 Chrysler dealerships.