Rising stock prices and interest rates cut the unfunded liabilities of the nation’s largest private defined-benefit pension plans by nearly three-fourths, the consulting firm Towers Watson reported Thursday.

At 93 percent, the funding is now at its highest level since the 2008 recession. The heftier investment returns cut the funding gap to $99 billion in 2013 from $384 billion in 2013 for the 418 Fortune 1000 companies sponsoring defined benefit plans.

During the past year, the companies cut their defined-benefit contributions by 30 percent to a total of $48.8 billion.

The consulting firm said the improved results will hasten the trend to reduce risk.