Sun Capital Partners III, LP, et al. v. New England Teamsters & Trucking Industry Pension Fund, et al., No. 12-2312, 2013 U.S. App. LEXIS 15190 (1st Cir. Jul. 24, 2013)

(private equity funds that actively manage operations of their portfolio companies are engaged in trade or business under ERISA and are not merely passive investors; immaterial whether fund has employees or if its management company has such employees and offices, but key is whether fund's activities exceed those of typical investor; impact of decision is that private equity funds may be liable for unfunded pension liabilities of their portfolio companies, and income from such fund is potentially subject to UBIT or withholding taxes; in addition court's decision means that income of private equity managers taxed at ordinary income rates rather than capital gain rates)