* Metrocall Holdings, an Alexandria wireless paging company, and Arch Wireless, a Westborough, Mass., company that plans to buy Metrocall, were sued by a Metrocall investor who claims the planned purchase is unfair. Shareholder Lyle Green said in a suit filed yesterday in Delaware that the deal is unfair to Metrocall shareholders, who would get $150 million in cash and a 28 percent stake in the combined business, while Arch shareholders would get the controlling stake. Metrocall will account for 36 percent of the combined company's revenue, according to Green. Arch and Metrocall both exited bankruptcy in 2002 and in March announced the plan to combine as Wizards-Patriots Holdings based in Alexandria. Shares of Metrocall fell 59 cents to close at $67.00.

* Northrop Grumman said its information technology sector in Herndon won a three-year contract worth up to $175 million from the Department of Homeland Security to implement and maintain a new human resources management system. The defense contractor will provide integration and program management for the new system.

* QuadraMed, a Reston health care information technology company, acquired all of the capital stock of Tempus Software, of Jacksonville, Fla., for $5.8 million in cash and more than 2.6 million shares of QuadraMed common stock. Tempus Software provides patient access management and technology services to health care facilities in the United States and Canada.

* Nextel Communications in Reston faces a potential obstacle to its proposal for new cellular airwaves from Sen. Frank Lautenberg (D-N.J.). The senator asked the General Accounting Office to review whether the Federal Communications Commission would be violating two laws that prohibit using federal funds without appropriation by Congress if it grants the airwaves. Verizon Wireless -- Nextel's rival and chief opponent of the FCC proposal -- this week said it would be asking lawmakers to request such a review. Although Lautenberg requested a GAO review by tomorrow, Gary L. Kepplinger, the agency's deputy general counsel, said a review typically takes 120 days. The agency will determine next week whether to accept the senator's request, he said.