usAT&T Inc on Friday said it plans to contribute a $9.5 billion stake in its wireless business to its underfunded pension plan. Earlier this week, Verizon Communications Inc moved to unload $7.5 billion in pension obligations to insurer Prudential Financial Inc.

But by far the most common trend in corporate America is to offer lump-sum payouts to thousands of retirees now – these voluntary buyouts could cost companies millions of dollars upfront, but they eliminate the risk of obligations soaring out of control in the future.

General Motors Inc and Ford Motor Co kicked off the trend earlier this year, and they have been joined this earnings season by companies ranging from Taco Bell and KFC owner Yum Brands Inc to tissue maker Kimberly-Clark Corp.

Companies "have been de-risking to manage the volatility of their (pension) assets," said Ari Jacobs, senior partner and Global Retirement Solutions Leader at Aon Hewitt. "The logical next step for organizations is to move liability off the balance sheet."