The funding ratio measures a pension's solvency, and 80 percent for many plans closed to new entrants has generally been considered a threshold in which they should be thinking about moving into fixed income to preserve gains. Falling below that level could delay a pension's move to the stability of fixed income assets that would help cushion portfolios from market volatility.
TURNING TO RISKY ASSETS
Among the underfunded corporate pension plans in Milliman's top 100 at the end of 2014 were Delta Air Lines Inc with a 42.8 percent funding level and American Airlines Group Inc at 62.4 percent.
AIG, which had a funded ratio of 70 percent at the end of last year, has targeted an increase in other investments to 31 percent this year from 17 percent in 2014, according to the company's 2014 annual report, while lowering its bond allocation to 27 percent from 28 percent in 2014.
American Airlines and AIG declined to comment.
In addition to heavily loading up on riskier investments, Delta is also pumping $1 billion a year into its pension through 2020.
Delta, whose funding level is the lowest among the Top 100 companies in the Milliman index, should reach an 80 percent funded ratio in the next five years, according to financial documents provided by the company.
Only 12 percent of the airline's pension is invested in fixed income with 21 percent in equities and the rest in other investments.
The airline has been severely underfunded over the last three years, with funding ratios of 46.9 percent in 2013 and 38.1 percent in 2012.
Frank van Etten, head of client solutions at UBS Global Asset Management, which oversees $695 billion in assets, said some pensions needed to take on more risk due to higher return targets.