WASHINGTON — Trade groups representing much of the U.S. financial industry are speaking out against cybersecurity legislation that has stalled this week in the Senate.

In a letter Wednesday to Senate leaders, nine industry groups, including the American Bankers Association and the Financial Services Roundtable, argued that the bill would add a layer of inconsistent and potentially duplicative regulation for financial firms.

"While we strongly support efforts to protect the nation's critical infrastructure from cyberattacks," the groups wrote, "this legislation threatens to undermine important cybersecurity protections already in place for our customers and institutions, and misses an opportunity to substantially improve cyber threat information-sharing between the federal government and the private sector."

The letter came as progress on the legislation, sponsored by Connecticut Sen. Joseph Lieberman, has stalled on the Senate floor. Republicans are demanding votes on a slew of unrelated amendments, which has drawn objections from Democrats. In addition, the U.S. Chamber of Commerce has reportedly been lobbying against the measure.

Late Tuesday, Senate Majority Leader Harry Reid scheduled a procedural vote for Thursday that would need 60 votes to allow the bill to move forward. But that vote is expected to fail unless party leaders can reach an agreement on the measure by Thursday.

The Senate bill differs considerably from a House version, passed earlier this year, which has more support in the financial industry. In their letter Wednesday, the groups said although the bill's authors had sought to establish a voluntary system for fighting cyberattacks, the legislation in its current form "would likely create a mandatory regulatory regime that could displace robust efforts already being made in the financial sector to combat the risk of cyberattacks."

Other industry groups signing Wednesday's letter were the Clearing House Association, the Consumer Bankers Association, the Securities Industry and Financial Markets Association, the Electronic Funds Transfer Association, the Financial Services Information Sharing and Analysis Center, the American Council of Life Insurers and Nacha, the electronic payments association.