Citing Microsoft Corp.'s lapses under part of a landmark antitrust settlement, the Justice Department said Friday it wants to extend by two years its oversight of some of the company's business practices until at least November 2009.

Microsoft has already agreed to the lengthier scrutiny by the department and 17 states under a proposal that still must be approved by a U.S. judge. The company has struggled with a key provision in the 2002 antitrust settlement requiring it to disclose to its competitors sensitive details about some of its software.

Government lawyers said they were prepared to extend oversight of Microsoft's business activities through 2012 if they deem it necessary. In court papers filed Friday, they described Microsoft's efforts under parts of the settlement as "disappointing" and "not very encouraging," but they also said Microsoft's failures were neither willful nor systematic.