The Pension Benefit Guaranty Corp. says if current regulations for its multi-employer-plan program do not change, there is “about a 65% chance” the program’s deficit will climb in 10 years.

In a “data book” released on Aug. 20, PBGC says a simulation model’s average result shows its multi-employer program will post an estimated deficit of $4 billion in 10 years, a 360% jump over its $869-million shortfall in fiscal 2009. PBGC cautions that the model is not “predictive.”

Multi-employer plans are common in construction’s unionized sector, PBGC says, and account for 54% of the 1,517 multi-employer plans it insures. Such construction plans covered 3.7 million participants, 36% of the total in the PBGC multi-employer program.