Defined benefit pension plan managers are thinking more about the possibility that plan beneficiaries may live longer than expected.

A unit of MetLife Inc., New York (NYSE:MET), has commented on that apparent shift in a report based in part on a survey of staffers at 166 corporate pension plans conducted in 2009 and 2010.

Most of the plans included had at least $100 million in assets.Mortality clock

Like annuity issuers and life settlement firms, pension plans tend to do better when beneficiaries live shorter lives than expected and collect fewer benefits payments.

In 2009, issues such as “meeting return goals,” “underfunding of liabilities” and “asset allocation” all received importance ratings over 45%, and “longevity risk” received an importance rating of just 6%.

In 2010, as the financial crisis eased, the importance ratings of “meeting return goals,” “underfunding of liabilities” and “asset allocation” fell to 20% to 30%, and the importance rating of “longevity risk” rose to 24%.

“Although some experts expect longevity increases to level off at a future point, others believe medical breakthroughs could increase life expectancy further in the future,” MetLife says.

- Allison Bell