On March 28, the US District Court for the District of Massachusetts held that, under the Employee Retirement Income Security Act of 1974 (ERISA), two private equity funds (1) were engaged in a trade or business, and (2) had formed a "partnership-in-fact" (which itself was engaged in a trade or business) that owned a controlling interest in a bankrupt portfolio company. Since the "partnership" owned 100 percent of the bankrupt debtor, the court found the funds jointly and severally liable for the debtor's $4.5 million multiemployer pension plan "withdrawal liability" despite neither fund owning ERISA's requisite 80 percent controlling interest in the debtor.