Morgan Stanley Dean Witter & Co. has discriminated against some female employees with inferior pay, promotions and terms and conditions of employment compared with their male counterparts, the U.S. Equal Employment Opportunity Commission said. The brokerage company immediately disputed the findings. The commission made the findings after studying the allegations of Allison K. Schieffelin, a principal in Morgan Stanley's Institutional Equity Division, which buys and sells stocks for institutional investors. Schieffelin, 39, had accused the company in 1998 of failing to promote her to the position of managing director because she is a woman. She said the company instead promoted men who were less qualified. A spokesman for Schieffelin said she wasn't available to comment.