Nearly 90 well-paid professionals will soon be out of work after their company lost a contract with a federal agency at Scott Air Force Base.

Local employees with Science Applications International Corp., based in McLean, Va., provide technical support services to the Defense Information Systems Agency at the air base.

Science Applications International and another company, URS-Apptis based in Chantilly, Va., are working under a combined $747 million one-year contract. Science Applications International began the original contract in October 2001 and extensions have expanded the contract's ceiling to $5.35 billion.

Company spokeswoman Jennifer Gephart said the company's O'Fallon branch learned in September the federal agency had chosen another contractor to provide technical support after the contract expires at the end of March.

"SAIC has provided approximately 89 employees working on the DISA contract with 60 days of notice of a possible reduction in force effective Feb. 15, 2013, which may result in permanent layoffs," Gephart said in a statement. "SAIC is committed to helping transition employees and minimize disruption to the community."

Gephart added the corporation will assist employees in finding employment within the company and elsewhere, including the new contractor serving the Defense Information Systems Agency. Gephart could not be reached for further comment on Wednesday.

Science Applications International still has multiple, ongoing contracts with U.S. Transportation Command and Air Mobility Command at Scott Air Force Base.

Layoffs may begin as soon as this Friday, according to a report required by state law to be sent to the Illinois Department of Commerce and Economic Opportunity.

Those working in the industry within St. Clair County averaged more than $105,000 in annual income in 2010, according to the U.S. Census Bureau.

In 2007, the company built a 14,000-square-foot building within the O'Fallon Professional Park. The company also has an additional office on Lakepointe Centre Drive in O'Fallon.

Contact reporter Daniel Kelley at dkelley@bnd.com or 618-239-2501.