REDMOND, Wash. Microsoft Corp. today announced revenue of $6.13 billion for the quarter ended Sept. 30, 2001, a 6 percent increase over the $5.77 billion reported in the prior year. Operating income totaled $2.90 billion compared to $2.78 billion in the prior year. Net income for the quarter was $1.28 billion including a $1.24 billion after-tax charge related to the impairment of certain publicly traded and private equity securities, predominantly in the cable and telecommunications industries. This charge is reflected in the $980 million investment loss reported this quarter. Diluted earnings per share for the September 2001 quarter were $0.23, including a $0.20 charge for net recognized investment losses which includes the impairment charge noted above.