A total of US$133 million in retirement benefits haven't been claimed, the federal agency that insures private pension plans has reported.

The Pension Benefit Guaranty Corp (PBGC) said 32,000 people are owed money. Individual benefits range from US$1 up to US$611,028. The average unclaimed benefit is about US$4,950.

"Although the vast majority of workers receive their full pension, sometimes people lose track of benefits earned with former employers," said Vince Snowbarger, the agency's interim director.

Online search

The agency urged people who may have lost track of a pension earned during their career and think they may be owed retirement benefits to conduct a search using PBGC's online directory - http://www.pbgc.gov/search

Pensioners can search by their last name, company name or state where the company was headquartered, the PBGC said.

The states with the most missing pension participants and unclaimed pension money are:

New York: 6,885 people, accounting for US$37.49 million in unclaimed benefits.

California: 3,081 people, US$7.38 million

New Jersey: 2,209 people, US$12.05 million

Texas: 1,987 people, US$6.86 million

Pennsylvania: 1,944 people, US$9.56 million

Illinois: 1,629 people, US$8.75 million

Florida: 1,629 people, $7.14 million.

The PBGC insures pensions for 44 million workers and retirees.

It was created in 1974 as a government insurance programme for traditional, defined benefit pension plans.

Those plans give retirees a fixed monthly amount based on salary and years of employment. Companies that sponsor these traditional pension plans pay insurance premiums to the agency. If a company cannot support its pension obligations, the agency takes over the plan and pays promised benefits up to certain limits.

To avoid missing out on your pension benefit, the PBGC advises workers to tell their employers when they move or change names. They also should hold on to any pension information they receive from their employer.

The agency's search tool identifies some 6,600 companies, many in the airline, steel, transportation, machinery, retail and financial services industries that closed pension plans in which some former workers could not be found, the agency said.