Needham (Mass.) Contributory Retirement Board is searching for a legal advisory firm, confirmed Evelyn M. Poness, chairwoman. Officials of the $100 million plan want to take a look at other candidates, Ms. Poness said, but the incumbent, the Law Office of Michael Sacco, is invited to apply. The RFP is available on the Massachusetts Public Employee Retirement Administration Commissions website at http://www.mass.gov/perac/new.htm. Proposals are due by 2 p.m. EDT April 30. Interviews may be scheduled for the week of May 14, and the three-year contract will likely be awarded May 30.