A new, controversial funding strategy used by pension funds is gaining steam.

Only in recent years has the climate been favorable for pension plans, mostly at large companies, to offload some of their future pension liabilities to insurers. To companies, it’s a way to guard against the unknown of dour investing returns or a surge in costs. For insurers, it’s a quick way to add billions of dollars in assets.

Some 21% of corporate pensions are “very or moderately likely” to explore this offloading tactic, where retirees draw their monthly checks from insurers such as Prudential Financial Inc. instead of their former employers, according to a new report from Aon Hewitt called, “2015 Hot Topics in Retirement.”

That’s up from 8% of firms who expressed a similar level of interest the previous year. For the report, around 183 companies were surveyed.

  WSJ Aon Hot Topics