The aggregate pension fund deficit of the United Kingdom’s largest companies fell by 13.5% over the course of 2003, according to Mercer Human Resource Consulting in London.

Mercer determined that the total pension fund deficit of the FTSE 350 companies was £64 billion ($114.57 billion) at the end of 2003, down from £74 billion ($119.13 billion) a year earlier.

Mercer studied the Dec. 31, 2003, year-end results of 158 of the FTSE 350 companies—the 350 largest publicly traded companies in the United Kingdom—and the projected positions of the remainder.

Tim Keogh, European partner at Mercer, said in a statement that the study showed that companies with pension fund deficits were “gritting their teeth and recognizing the need to increase contributions.”

He noted that although there had been an increase in equity values over the past year, the effects of that change were tempered by a drop in bond yields—which are used to measure plans’ liabilities—and the increased longevity of plan participants.

Mr. Keogh also noted that while pension fund deficits were, on average, equal to about 3% of the company’s market capitalization, in one in 10 cases, this proportion rose to 20% or more.