Government scrutiny of

Boeing

(BA) - Get Report

appears to be widening, with federal prosecutors reportedly now looking at a $100 billion Army program Boeing oversees.

The U.S. Attorney's office in Alexandria, Va., which has been investigating Boeing's dealings with the Air Force, is making preliminary probes into Boeing's role as lead contractor in the Army's Future Combat System, according to

The Wall Street Journal

, which cited unidentified sources familiar with the matter.

Prosecutors have not alleged any improprieties, and it isn't clear where the inquiries might lead, the report said.

The broadened investigation involves Michael Sears, Boeing's former chief financial officer, the report said. Sears was fired late last year after an ethics scandal erupted over Boeing's procurement of Air Force contracts. Darleen Druyun, a former Defense Department acquisition official, has admitted to favoring Boeing while she negotiated a $250,000-a-year Boeing job and employment for family members. She received a nine-month prison sentence last month.

In response to the report, Boeing spokesman Douglas Kennett said he was not aware of prosecutors pursuing a new line of questioning into the Army program and had not been informed by the U.S. Attorney of details of its investigation into Michael Sears.

The Future Combat System has been subject to numerous reviews and is "executing to plan," Kennett said in a written statement. "We are confident that the FCS program has been very well structured from the beginning."

Boeing shares rose 47 cents, or 0.9%, at $52.34.