The Brockton Contributory Retirement System is seeking information from alternative strategy investment managers on various asset classes, including bank loans, mezzanine lending and distressed debt. The $200 million plan is doing an annual rebalancing of its fund and is looking at some new asset classes of which distressed debt is one, said Harold Hanna, executive director of the retirement system. The investment will be funded with up to $20 million. Wainwright Investment Counsel is assisting the plan and has sent out a request for information. Though some funds are looking at bank loans as a hedge against rising interest rates, Hanna said the potential rise in interest rates is not a factor.