NEW YORK (CNNMoney.com) -- Legislation expected to be voted on in Congress as soon as this week to reform the nation's private pensions could actually increase the burden on the federal pension agency, according to a published report.

The Wall Street Journal reported Monday that a study by the Pension Benefit Guaranty Corp., the agency that is on the hook for retirement obligations of failed pension plans, suggest that the agency would have to make more pension payments for companies unable to do so themselves over the next decade if the pension reform legislation passes.

Some congressional staffers called the PBGC's analysis flawed, in part because they say it overestimates what companies would have to contribute to their pension funds under current rules, according to the paper.

The legislation, which would change the minimum requirements for employers' contributions to their pension plans, is designed to keep pensions better funded and make it less likely the PBGC will have to assume their obligations.

The PBGC estimates that under current law the agency will absorb an estimated $12.8 billion in claims, or pension obligations from 2007 to 2016, the paper reported.

By contrast, the agency estimates that proposals under consideration by congressional negotiators would swell the agency's obligations by $14.9 billion to $15.2 billion in claims over the decade, according to the report.

The paper also reports that the study estimates companies will make $1.24 trillion in contributions to their plans in the next decade, while it forecasts that the legislation would result in contributions of $1.21 trillion to $1.23 trillion.

The Journal reports that both Democrats and Republicans have continued to insist that the compromise proposal will be tougher than current law.

House Majority Leader John Boehner has criticized the PBGC modeling, according to the paper, saying it doesn't take into account some of the provisions in congressional proposals.

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