BOSTON - A federal district court erred in concluding that private equity funds that invested in a company that later went bankrupt were not liable for the company's withdrawal liability under the "trades or businesses" aspect of the two-part "control group" test under the Multiemployer Pension Plan Amendments Act of 1980 (MPPAA), the First Circuit U.S. Court of Appeals ruled July 24 on an issue of first impression (Sun Capital Partners III, LP, et al. v. New England Teamsters & Trucking Industry Pension Fund, et al., No. 12-2312, 1st Cir.; 2013 U.S. App. LEXIS 15190).