Detroit emergency city manager Kevyn Orr on Monday delayed a pension freeze he ordered last month while courts negotiate in mediation for how best to deal with an estimated $3.5 billion pension underfunding. Orr’s Dec. 31 executive order suspended pensions, eliminated cost-of-living increases, and created a 401(k)-style plan for the city’s 5,600 active workers and 12,000 retirees in the general retirement system. Although the move only affected non-uniformed city workers, Orr had indicated he would soon make a similar order for the city’s police and fire retirement system. But the move came under sharp criticism from the city’s unions, and Orr’s spokesman said Monday that he agreed to hold off while a federal judge reviews the city’s bankruptcy proceedings.