The Supreme Court yesterday rejected an attempt by Marine Lt. Col. Oliver L. North to block the criminal investigation into his activities in the Iran-contra affair.

The justices, without comment, let stand a federal appeals court ruling upholding the authority of Attorney General Edwin Meese III to delegate prosecutorial power to independent counsel Lawrence E. Walsh. Walsh had issued a subpoena for samples of North's handwriting and North responded by challenging his authority to do so.

Walsh was appointed originally by a special three-judge panel acting under the Ethics in Government Act. Meese made the backup appointment last March, 10 days after North challenged the Ethics Act, giving Walsh the attorney general's law enforcement powers.

Yesterday's action, which means North must comply with the subpoena or face jail on contempt charges, focused on Meese's parallel appointment of Walsh to investigate the matter, not on the constitutionality of the office of the independent counsel.

Still pending is a constitutional challenge to the law brought by former Justice Department official Theodore B. Olson, a target of an investigation by independent counsel Alexia Morrison. A three-judge appeals panel heard arguments in that case last September.

Justice Department spokesman Terry Eastland said he was "gratified" by the high court action. Although the department believes the independent counsel provisions of the Ethics Act are unconstitutional, Eastland said, the action left intact the appeals court decision that Meese "has the authority to appoint an independent counsel like Judge Walsh."

Although the court's action was not expected to affect the timing of any possible indictments from Walsh's investigation, a spokesman for his office said the justices had lifted a legal cloud.

Spokesman Jim Wieghart said, "We are pleased that any question as to the authority of this office to carry on its investigation of the Iran-contra matter has now been laid to rest by the court."

Even if the high court were to rule later that the Ethics Act was unconstitutional, Wieghart said, it appears that Walsh's office could proceed under its parallel appointment.

Sources familiar with the investigation into the sale of arms to Iran and the diversion of profits to aid rebels fighting the Nicaraguan government say indictments are expected by the end of March.

Those expected to be charged include North, who was fired from the National Security Council after his actions were revealed, former national security adviser John M. Poindexter, retired Air Force major general Richard V. Secord and Secord's business partner, Albert Hakim.

In other action yesterday, the justices:

Agreed to decide the constitutionality of a Colorado law making it a crime to pay people to collect signatures for petitions for statewide initiatives. A federal appeals court in Denver struck down the law as a violation of the First Amendment. The law involved in Meyer v. Grant is similar to ones in Maryland and the District that were struck down by federal judges.

Declined to disturb a ruling that a jury must consider a copyright dispute involving singer-songwriter Lionel Ritchie and one of his songs, "Stuck on You." Another songwriter, Gene Thompson, claimed that Ritchie stole the lyrics and melody from him.

Let stand the perjury conviction of Mississippi federal judge Walter L. Nixon Jr., who faces a five-year prison sentence after his conviction by a jury in 1986.

Agreed, in a case from Maryland, to decide whether the government can be sued by a woman injured during a Navy serviceman's drunken shooting spree. Mary Sheridan, who was traveling in a car driven by her husband, was hit by bullet fragments from several rifle shots fired by Navy medical aide Robert W. Carr.

Sheridan sued the government, claiming the Navy was negligent in allowing Carr to keep a rifle in his quarters at the Bethesda Naval Medical Center and in not responding to Carr's alleged mental instability.

The court, with its docket for the current term nearly full, is expected to hear arguments in Sheridan v. U.S. in April.