Shares of America Service Group ( ASGR) were among the Nasdaq's losers Monday, falling 13% after the company lowered its 2005 earnings guidance.

The company now expects earnings of $1.43 to $1.50 a share, down from previous guidance of $1.45 to $1.52 a share. America Service Group said its revised guidance includes the expected expiration of its Hillsborough County contract and weaker-than-expected July operating results, which were blamed on the losses incurred in its Idaho Department of Corrections and Indiana Department of Correction contracts. The company's Idaho contract expired July 11, and its Indiana contract is set to expire on Aug. 31.

America Service said that it still expects 2005 sales of $640 million to $660 million. Analysts polled by Thomson First Call are expecting 2005 earnings of $1.47 a share on sales of $651.1 million. Shares were trading down $2.40 to $16.15.

Mantech International ( MANT - Get Report) said on late Friday that its chief financial officer is leaving the company to join ICX Technologies. Kevin Phillips, Mantech's corporate vice president and chief of staff, will replace Ronald Spoehel. Phillips will serve as interim CFO until a permanent replacement is found, the company said. Shares were recently trading up 42 cents to $29.78.

Shares of Millennium Cell ( MCEL) rose 5% after the hydrogen battery technology company received a follow-on award to continue its program with the U.S. Air Force's Advanced Power Technology Office and the Department of Defense Fuel Cell Test and Evaluation Center, which is being operated by Concurrent Technologies. During the second year of the program, Millennium will develop a solid borohydride fuel module for the 5kW system that was successfully demonstrated at the Fuel Cell Test and Evaluation Center during the program's first phase. Shares were trading up 11 cents to $2.39.

Northrop Grumman ( NOC) rose modestly after the defense contractor said it would reaffirm its 2005 and 2006 guidance during investor meetings later this week. In late July, Northrop said that it would post 2005 earnings of $3.90 to $4 a share on sales of $31 billion to $31.5 million. During 2006, the company expects earnings of $4.10 to $4.30 a share on sales of about $32 billion. Analysts are expecting 2005 earnings of $4 a share on sales of $31.37 billion and 2006 earnings of $4.25 a share on sales of $32.47 billion. Shares were trading up 4 cents to $55.59.

Shares of Harris ( HRS) traded actively after the company increased its quarterly dividend by 33% to 8 cents a share. "We are delighted to announce this increase in our quarterly dividend," Harris said. Harris reported record results in the recently concluded fiscal year 2005, and we expected continued positive momentum in the current year for both our government and commercial segments, driven by expanding market opportunities and confidence in our strategies that address those opportunities." The dividend will be payable on Sept. 16 to shareholders of record on Sept. 7. Shares were recently trading down 62 cents to $36.57.

NYSE volume leaders included Lucent Technologies ( LU), unchanged at $3.04; Procter & Gamble ( PG), up 32 cents to $55.28; Exxon Mobil ( XOM - Get Report), down 6 cents to $58.35; PanAmSat ( PA), up $4.11 to $23.91; Citigroup ( C - Get Report), up 7 cents to $43.17; Gillette ( G), up 37 cents to $53.61; and General Electric ( GE), down 12 cents to $33.26.

Nasdaq volume leaders included Microsoft ( MSFT), up 4 cents to $27.01; Intel ( INTC), up 19 cents to $25.60; Sun Microsystems ( SUNW), up 2 cents to $3.69; Cisco Systems ( CSCO), up 6 cents to $17.46; Capstone Turbine ( CPST), up 34 cents to $4.53; Sirius Satellite Radio ( SIRI), down 4 cents to $6.66; and Oracle ( ORCL), up 10 cents to $13.