Maryland Attorney General Francis B. Burch advised Gov. Marvin Mandel yesterday that the state's recently passed death penalty bill is defective and should be vetoed or severely amended in the next legislative session.

Burch said the capital punishment measure appears constitutional in its present form, but "leaves so many loose ends and possesses so many interpretive problems" that its administration would prove difficult.

The opinion was sent to Mandel on Tuesday and released Wednesday afternoon, less than 24 hours before Lt. Gov. Blair Lee 3d was to sign several hundred bills at a ceremony in Annapolis, acting for the ailing Governor. As of last night, according to Mandel's legislative office, the death penalty bill was not among those to sign today.

Sources close to Mandel said administration thinking at this time is that the governor will sign the death penalty measure and then follow through on Burch's advice that it be further amended in the next session of the General Assembly.

Burch's opinion is expected to further delay implementation of the death penalty in Maryland even if Mandel signs the measure. One official close to Mandel pointed out that state judges probably would be very reluctant to use the law until it was revised.

These sources noted that the politically popular measure was pushed through the legislature this year on Mandel's initiative, thus making in unlikely that he would turn around and veto it. They also said Mandel had discussed several potential problems with the bill with Burch before the opinion was released.

The death penalty bill was drafted specifically to meet U.S. Supreme Court and Maryland Court of Appeals objections to previous death penalty bills. It requires separate trials to determine sentencing for persons convicted in previous trials of crimes subject to the death penalty.

he major defect, Burch wrote, was that the bill did not provide specific guidelines for jurors to hlep them make up their minds whether a criminal should be put to death. The bill fails to tell them how much proof is needed by the prosecutors to show that the death penalty is required and, at the same time, how much evidence a defendant should have before the jury should believe claims of "mitigating circumstances" that would warrant a lesser sentence, Burch said.

"There is no assurance whatsover that one trial judge will adopt the same burdens of proof and instruction as another trial judge," said Burch. "It is distinctly possible that defendants will be tried in various jurisdictions throughout the state under different burdens of proof and different jury instructions."

Burch said he expected that defect would eventually be corrected by an appeals court, but added: "The uncertainty which will exist in the meantime . . . will hardly be conducive administration of a capital punishment law which the Supreme Court has set forth as the constitutional objective."

The three minor defects Burch found in the bill included: the lack of a clear requirement for pretrial notification to the defendant that the death penalty will be sought; uncertainty about the degree of specificity required by the jury in giving its recommendation; and what Burch called "the problem surrounding the hung jury possibility, i.e., where a jury splits on the sentence recommendation."

The capital punishment measure was dispatched to Mandel on April 8 after being passed by the House of Delegates on an 81-to-44 vote. The Senate had approved the bill one month earlier by a much narrower margin, 25 to 22.

The deliberations over the death penalty in Maryland this session marked the fourth consecutive year state lawmakers wrestled with the problem following the U.S. Supreme Court's 1973 decision striking down capital punishment laws in 37 states, including Maryland.