Solving the union pension crisis will remain the top priority next year for the agency that insures private pensions, as it completes its regularly scheduled programming to help retirees and plan sponsors.

A bicameral congressional committee tasked with fixing the multiemployer pension system, which includes pensions collectively bargained with multiple employers by unions, didn’t come up with a solution before its deadline.

The failure to reach an agreement means the Pension Benefit Guaranty Corporation-backed system is still headed toward insolvency...