Sidley Austin has agreed to pay a $27.5 million settlement to end a closely watched age discrimination suit brought by the U.S. Equal Employment Opportunity Commission on behalf of 32 former partners.

The partners at issue, most of whom were in their 50s or 60s, were demoted to counsel status in 1999 by the firm then known as Sidley & Austin. All but around 10 of them ultimately left the Chicago-based firm. In a January 2005 lawsuit filed after a lengthy investigation, the EEOC charged that the demotions were made in violation of the federal Age Discrimination in Employment Act. The firm claims the demotions were based on performance.