Well-known UK employers such as Grand Metropolitan, Ladbroke and BOC, provide inferior pension benefits to their competitors, according to a survey of about 300 occupational schemes.
By contrast, MPs enjoy the best pension funds and generous schemes include those provided by BP, Schroders, Barclays and Marks & Spencer.
Pension Scheme Profiles 2000 is compiled by trade union pensions expert Bryn Davies and rates 275 funds from across the UK for level of benefits and employer contribution against a target level of 100 per cent.
A key factor in employers improving their rating this year was the scrapping of "clawback" - the practice of offsetting benefits against the level of the basic state pension. Employers which have scrapped or reduced clawback recently include oil giant BP Amoco and Barclays Bank.
The annual survey - put out under the Unions Pension Services imprint - has drawn criticism in the past for attempting to pit company pension schemes against each other, but Davies defended the publication.
"While all these schemes offer worthwhile benefits, members are entitled to know how well the benefits provided by their scheme compare with those offered by similar employers."