NEW YORK – General Motors’ deal to cut pension obligations by $26 billion and shift plans to Prudential Financial appears to be fueling more such transfers as U.S. employers face a collective retirement-funding shortfall the size of Greece’s debt.

MetLife and Prudential are among insurers that expect the GM deal to encourage more corporations to offload plans. Pension liabilities exceed assets by more than $435 billion, according to a Bloomberg review of data disclosed by firms in the Russell 1000 Index of large U.S. companies.

Greece, facing demands for austerity measures in exchange for rescue funds, had total debt of about $450 billion at the end of 2011.

Employers who endured two stock-market crashes in a decade and 10-year Treasury yields near a record low may be tempted to follow GM’s lead by paying insurers to take the risk that market returns are inadequate or that beneficiaries live longer than expected.

Transferring the obligations can reduce swings in earnings tied to securities and relieve companies of the need to manage large pools of money.

There “may be a greater willingness to pull the trigger and execute a transaction,” said Robin Lenna, executive vice president of MetLife’s corporate benefit funding group. “They have a model. Somebody already did it in a big way.”

GM, the largest automaker, said most of the 118,000 retirees and surviving beneficiaries affected by the shift will get Prudential annuities, with about 42,000 having the option of lump-sum payments.

GM pensions were underfunded by $25.4 billion, the largest gap among the biggest U.S. companies, as of Dec. 31. The Detroit-based firm had global pension obligations of about $134 billion.

GM will contribute $3.5 billion to $4.5 billion in cash to the salaried pension plan to help fund it and purchase the annuities from Newark, N.J.-based Prudential, GM Chief Financial Officer Dan Ammann said. The transaction will be completed by the end of this year, the company said.

“The pension world will forever remember this transaction as the beginning of the era of pension de-risking,” said Dylan Tyson, head of pension risk transfer at Prudential, the No. 2 U.S. life insurer. “This is a market whose time has come.”

Growth had stalled before the GM deal, with carriers having $48.2 billion of group annuity assets on their books as of Dec. 31, compared with $48.8 billion three years earlier, according to a survey of eight insurers by trade group Limra.

The federal Pension Protection Act, which was passed in 2006, gave employers seven years to fully fund their retirement plans and required them to use an interest rate based on a basket of corporate bonds to compute liabilities. As bond yields decline, corporate pensions must set aside more money to cover future obligations.

The employers most likely to transfer obligations have high cash levels and “meaningful” underfunded retirement obligations, said Stephen Brown, an analyst at Fitch Ratings.

Timken Co. is among firms that may follow GM’s path. The maker of bearings has spoken with Prudential and other insurers about annuitizing its pensions, which have $2.6 billion in assets and $3.1 billion in liabilities, said Glenn Eisenberg, the Canton, Ohio-based company’s executive vice president of finance and administration.

Timken this year began offering retiring employees the option of receiving benefits in a lump sum, Eisenberg said. Contributions to the company’s pension plans consumed $521 million since 2010 and are expected to cost $165 million this year, according to a company filing.

Every 25-basis-point reduction in the discount rate the company uses causes its liability to increase about $70 million, Eisenberg said.

“We had put cash into the plans and gotten them fully funded, only to see interest rates continue to drop over the last decade while asset returns were volatile,” Eisenberg said. “That caused these big unfunded positions, and we had to throw more cash into it.”

To pay for the transaction, Timken must fully fund the plans and contribute about an additional 15 percent of their assets as a premium to compensate the insurance company it eventually chooses, he said.

Ford, the No. 2 U.S. automaker, is offering lump-sum payments to about 98,000 U.S. salaried retirees and former employees.

Ford rejected offloading its obligations to a separate company in favor of investing in global expansion and new models and paying dividends, CFO Bob Shanks said June 4.

“We’ve looked at all sorts of options,” Shanks said in an interview. “It’s not like it’s rocket science. There’s only so many things you can do to de-risk a pension plan.”

The Russell 1000 companies reviewed by Bloomberg are projecting an average return on pension assets of 7.3 percent. That’s down from 7.5 percent a year ago, and still above annualized returns over the past 10 years of 6.44 percent reported by corporate funds with assets greater than $1 billion, according to Wilshire Trust Universe Comparison Service.

“There’s really been almost a decade and a half now of an awful lot of ups and downs and, frankly, more downs than ups in terms of pension plan financing,” said Rick Jones, leader of the retirement consulting national practices at Aon.

“The volatility has taken its toll on many CFOs.”