WASHINGTON—Employers in bankruptcy whose pension plans are taken over by the Pension Benefit Guaranty Corp. would have to pay a huge new premium to the PBGC after they emerge from bankruptcy under legislation to be taken up by a Senate committee this week.

The provision, part of a broader pension funding reform measure unveiled late last week by Senate Health, Education, Labor and Pensions Committee Chairman Mike Enzi, R-Wyo., would require employers terminating underfunded plans to pay the PBGC a premium of $1,000 for each plan participant. The new levy would be paid annually in the three years following an employer's emergence from bankruptcy.

The new proposed mandate, which would apply for plan years starting Jan. 1, 2006, is a response by legislators to concerns that the regular premiums employers pay the PBGC cover only a fraction of the liabilities the agency assumes when it takes over plans of financially troubled companies.

Other provisions in the legislation would boost the base PBGC premium to $30 per plan participant from the current $19 level, require employers to amortize pension liabilities over 10 years, and require employers to value plan liabilities based on plan demographics.

Provisions to give cash balance plans more protection from age discrimination suits still are being worked out, sources said.

Somewhat different bills, all aimed at improving the financial base of the PBGC, previously were approved by the Senate Finance Committee and the House Education and the Workforce Committee.