This document provides notice of a public hearing on proposed regulations (REG-151135-07, 2008-16 I.R.B. 815) providing additional rules for certain multiemployer defined benefit plans that are in effect on July 16, 2006. The regulations affect sponsors and administrators of, and participants in multiemployer plans that are in either endangered or critical status. The regulations are necessary to implement the new rules set forth in section 432 that are effective for plan years beginning after 2007. The regulations reflect changes made by the Pension Protection Act of 2006. A public hearing is scheduled for July 31, 2008.