The funding ratio among corporate plans dropped to 84% as of May 31 from 84.5% as of April 30, said a report from Milliman.

Discount rates dropped to 2.76% in May, offsetting the month's investment gains of 1.85%, the report said.

In May, Milliman's Pension Funding Index (PFI) funding deficit grew to $306 billion as discount rates dropped to 2.76%, near