NEW YORK -- President Obama rebuked Wall Street for risky practices Thursday even as he sought its leaders' help for "updated, commonsense" banking regulations to head off any new financial crisis.

"Ultimately there is no dividing line between Main Street and Wall Street. We rise or we fall together as one nation. So I urge you to join me," Obama said in a high-stakes speech near the nation's financial hub. His audience included some of the nation's most influential bankers.

The president acknowledged differences of opinion over how to best protect bailout-weary taxpayers but denounced criticism from some Republicans who claim a Democratic-sponsored bill headed for Senate action would encourage rather than discourage future bailouts of huge banks.

"That makes for a good sound bite, but it's not factually accurate. It is not true," Obama said to scattered applause. "In fact, the system as it stands -- the system as it stands is what led to a series of massive, costly taxpayer bailouts." He said the overhaul legislation would put a stop to such bailouts.

Obama's speech came at a delicate time in negotiations over the Senate measure, which could be debated next week. The House has passed its own version of financial overhaul legislation. Obama did not say which one he favored but told an audience that included dozens of financial leaders "both bills represent significant improvement on the flawed rules we have in place today."

Obama portrayed his appearance at Cooper Union college, in lower Manhattan, as a reprise of a campaign speech he gave at the same location in March 2008 to offer an agenda for financial regulatory reform.

"Since I last spoke here two years ago, our country has been through a terrible trial," he said, pointing to the loss of more than 8 million jobs, the losing of "countless small businesses," trillions of dollars in lost savings and people forced to put off retirement or postpone college.

Taking his argument for stronger oversight of the financial industry to the city where the economic meltdown began, Obama said it was "essential that we learn the lessons of this crisis, so we don't doom ourselves to repeat it. And make no mistake, that is exactly what will happen if we allow this moment to pass."

Obama's efforts to give the financial bill a personal push toward the finish line drew skepticism from his critics.

"The truth is, the American people have had enough of the federal government," said House Republican leader John Boehner of Ohio. He said Obama-backed legislation "will enrich Wall Street at the expense of every other financial institution in the country."

The U.S. Chamber of Commerce took out full-page ads in New York papers recognizing a need for reforms but criticizing provisions of the current legislation. "Mayor (Michael) Bloomberg has pointed out that beating up on Wall Street may be good short-term politics -- but not if it gets in the way of right solutions," the chamber said in its "Open Letter to the President."

Bloomberg, who has expressed reservations over the overhaul legislation, was in the audience of about 700 financial industry leaders, consumer advocates, presidential advisers, local officials, students, faculty and others for Obama's speech.

Sponsors still held out hope that the Senate measure would draw some cautious Republican support. At the same time, Senate Majority Leader Harry Reid, D-Nev., told reporters he's prepared to hold a procedural test vote Monday if bipartisan negotiations fail to yield an agreement.

Obama's speech was an effort to ramp up pressure on Congress. He also used it to take the financial industry to task. "A free market was never meant to be a free license to take whatever you can get, however you can get it," Obama said.

He called on the financial leaders to tone down what he called "furious efforts" by an army of lobbyists to derail or water down the legislation. "I am sure that many of those lobbyists work for some of you," he said.

The sweeping regulation proposal represents the broadest attempt to overhaul the U.S. financial system since the 1930s, and aims to prevent another crisis. Democrats are preparing to bring the Senate version of the bill up for debate, but solid GOP opposition has complicated the effort. Senate negotiators say they had made progress toward a compromise bill that could command support from both sides.

Reform review

Under key provisions of financial regulation legislation proposed in the Senate:

--A nine-member Financial Services Oversight Council made up of the Treasury secretary, Federal Reserve chairman, a presidential appointee with insurance expertise, heads of regulatory agencies and the head of a consumer protection bureau would monitor financial markets and watch for threats.

--A mechanism would be set up under the Federal Deposit Insurance Corp. to liquidate failing firms that are too large and interconnected to undergo bankruptcy. A $50 billion fund, financed by large financial institutions, would help pay. Additional costs would be assessed to the industry.

--A Consumer Financial Protection Bureau within the Federal Reserve would police lending, taking powers now exercised by various bank regulators. But those regulators could appeal bureau regulations to the oversight council.

--The Federal Reserve would lose supervision of thousands of banks but would police larger bank-holding companies and large, interconnected nonbank institutions that the oversight council determines could pose a threat to the economy. With council approval, the Fed could break up large, complex companies that pose a grave threat to the financial system.

--Trades of derivatives, the complicated financial instruments blamed for accelerating the Wall Street crisis, would have to take place in regulated exchanges.

--Regulators would devise rules to prohibit bank-holding companies with commercial bank operations from speculative trading on their own accounts. Large, interconnected companies would have to put more money in reserve.

--Shareholders would have the right to cast nonbinding votes on executive pay packages.

Jim Kuhnhenn and Sara Kugler of the Associated Press contributed to this report.