WASHINGTON — Senate efforts to craft a bipartisan deal on overhauling financial-market rules have stalled amid disputes over a proposed consumer-protection agency, raising another hurdle in the White House's effort to revamp banking regulation.

Republicans led by Alabama Sen. Richard Shelby have intensified their opposition to the administration's consumer measure.

"I don't see any resolution to the consumer protection proposal," Sen. Shelby said in an interview. "I wouldn't support it."

Getty Images Senate Banking Committee Chairman Christopher Dodd, left, confers with Sen. Richard Shelby during a hearing on Capitol Hill recently.

Senate Banking Committee Chairman Christopher Dodd (D., Conn.) and Sen. Shelby, the panel's top Republican, have been in talks for months about revamping financial regulations.

Sen. Dodd told Democratic colleagues at a meeting a month ago that he was hopeful a deal could be reached. But he vowed to move forward on his own, if necessary.

Aides to Sens. Dodd and Shelby have met regularly to comb through complex details of derivatives, bank regulation, securitization and financial-market oversight. But the consumer agency has been the biggest stumbling block by far.

Both sides remained hopeful a compromise could be worked out. But the tone has become more partisan, with neither side indicating it would budge, people familiar with the matter said.

Democrats say a consumer-protection agency to police mortgages and credit cards is vital to any overhaul of financial rules. President Barack Obama has advocated for it. Liberals and union groups have pushed for it aggressively. Democrats could splinter if Mr. Dodd scrapped it.

House Republicans also largely oppose a consumer agency. But two weeks ago, Democrats were able to muscle a bill through the House Financial Services Committee that included such an agency — with a single Republican voting for it — and the House financial-regulation package is expected to pass.

Sen. Shelby reacted to the House action by calling the consumer agency "the nanny state at its worst."

Democrats say Sen. Dodd has enough Democratic support to push the bill through his panel. But a party-line vote in committee would make Senate passage less certain because of the misgivings of some moderate Democrats. Sen. Dodd's staff has nevertheless started to draft legislation, even though Sen. Shelby said "we haven't reached an agreement on any concrete items."

Some Republican aides believe the White House might be willing to drop the consumer agency if it gets assurances that the rest of its proposal, such as the creation of new standards to oversee large financial institutions, would win some Republican backing. But Senate Democrats and White House officials so far aren't budging on the consumer agency.

"There needs to be an independent agency that looks out for people when they take out a loan, open a checking account or use a credit card," Sen. Dodd said earlier this month.

Acknowledging the sensitivity of negotiations, White House and Treasury Department officials have intensified their outreach to moderate Senate Democrats to gauge their concerns.

Capitol Hill aides said a vote in Sen. Dodd's panel on the proposal is expected around Thanksgiving, and the issue likely won't move to the Senate floor until January or February.

"We'll find a consensus and we'll have a better package because we've incorporated more people's ideas," a spokeswoman for Sen. Dodd said.