WASHINGTON (AP) - The Supreme Court said Monday that state attorneys general can investigate national banks for discrimination and other crimes, but only with a court's help.

The high court ruled that a state attorney general cannot on his or her own issue a subpoena against a bank that has branches in that state and others. However, the court said national banks are subject to some state laws under the National Banking Act, and an attorney general can go to court to enforce those laws.

"What this decision today says is that states have the ability to enforce their own laws (against national banks) as long as they follow state due process procedures, which generally mean issuance of a subpoena which can be challenged in court," said lawyer John Cooney, a former assistant solicitor general and deputy general counsel at the federal Office of Management and Budget.

Officials say that this decision opens the door for states to do their own investigations of national banks, as long as they can convince a judge that it is needed.

The State of New York had asked the Supreme Court to overturn a federal appeals-court decision that blocks states from investigating the lending practices of national banks with branches within its borders. It was supported by the other 49 states.

New York Attorney General Andrew Cuomo called it "a huge win for consumers across the nation."

"I am pleased that the court has turned back efforts by the nation's largest banks to prevent the efforts of New York and other states to protect consumers from predatory financial practices," he said. "With this decision, the court has recognized that fair lending and consumer protection - the cornerstones of a sound economy - require the cooperative efforts of both the states and the federal government."

Eliot Spitzer, then New York's attorney general, wanted to investigate whether minorities were being charged higher interest rates on home-mortgage loans, a practice that is prohibited under various state and federal laws. But federal judges said Spitzer could not enforce state fair-lending laws against national banks or their operating subsidiaries by issuing subpoenas and bringing enforcement actions against them.

"Here, the threatened action was not the bringing of a civil suit, or the obtaining of a judicial search warrant based on probable cause, but rather the attorney general's issuance of subpoena on his own authority," said Hon. Antonin Scalia, who wrote the opinion for the court. "That is not the exercise of the power of law enforcement ‘vested in the courts of justice,' " which the National Banking Act allows.

Both the Clearing House Association, which represents the banks, and the comptroller said the attorney general was interfering with the federal government's supervisory powers.

"In holding that the OCC regulation at issue in Cuomo was invalid, the court has reaffirmed the authority of the sovereign states to police corporate actors within a state and protect their citizens," said Sen. Patrick Leahy, D-Vt., and chairman of the Senate Judiciary Committee. "And the court has rightly rejected the national banks' attempt to hide behind an unreasonable agency regulation in order to escape scrutiny from state authorities."

Edward Yingling, president and CEO of the American Bankers Association, said he was disappointed with the court's decision.

"Without a uniform regulation and enforcement of the laws that apply to national banks, which often includes state law, those institutions will face a patchwork of duplicative and conflicting federal and state regulation and enforcement actions," he said. "This will make it difficult to serve consumers in today's high-tech, mobile society where people and bank services move constantly across state lines."

The 2nd U.S. Circuit Court of Appeals in New York City had ruled that the responsibility for such investigations rests with the Office of the Comptroller of the Currency, a part of the Treasury Department, and other federal agencies.

"Channeling state attorneys general into judicial law-enforcement proceedings (rather than allowing them to exercise ‘visitorial' oversight) would preserve a regime of exclusive administrative oversight by the comptroller while honoring in fact rather than merely in theory Congress's decision not to pre-empt substantive state law," Scalia said.

Chief Justice Hon. John Roberts, Hon. Clarence Thomas, Hon. Samuel Alito and Hon. Anthony Kennedy dissented in part, saying they would have ruled with the New York-based appeals court.

The case is Cuomo v. The Clearing House Association, 08-453.