The Manhattan district attorney, Robert Morgenthau, called for a reform of Rockefeller-era drug laws yesterday, as state legislators renew talks this week on changing laws that carry some of the harshest penalties in the country.

“I raise these issues now, in the hope that lawmakers, who will be back in Albany this week, will use the time to consider both changes in the law and more resources for treatment and prevention,” Mr. Morgenthau said, referring to the 1973 law that imposes mandatory sentences for drug-related felony offenses.

The Rockefeller laws are ineffective, as a convict serving a mandatory sentence of three to nine years could get out on work release in six months, Mr. Morgenthau said. Placing nonviolent, first-time drug offenders into treatment programs would be more effective and could spare the taxpayer tens of thousands of dollars per defendant, the district attorney said.

Mr. Morgenthau proposed a system of “determinate” sentencing, in which sentences handed down by a judge would bear a closer relation to the term served by the convict, as well as greater discretion for judges in setting sentences, a “kingpin statute” that would reserve top felony charges for drug gang leaders, and more financing for treatment services.

“It’s a two-sided problem, a supply-and-demand problem,” said Mitchell Rosenthal, president of the treatment program Phoenix House. “The law deals with the supply problem, but it also has to deal with the demand problem with drug treatment and evaluation.”

Mr. Morgenthau cited the Drug Treatment Alternative to Prison program, implemented by the Brooklyn district attorney, Charles Hynes, in 1990. Of 1,696 people who entered the two-year drug-treatment program after being convicted for the first time of felony drug offenses, 62% graduated.

Speaking out against the Rockefeller drug laws could pay off in today’s political climate. In Albany County, David Soares, a Democrat, was elected district attorney last month after making drug-law reform a major part of his platform. Mr. Soares defeated a tough talking incumbent, Paul Clyne, in the Democratic Party primary.

“He was running on a Rockefeller-drug-law-reform platform against an incumbent district attorney who had been an outspoken defender of the current drug law, of the status quo,” said a spokesman for the Working Families Party, Alex Navarro. “That cleared the groundwork for a very respected prosecutor like Mr. Morgenthau to make clear that he also favors reform.”

Advocates for drug reform lauded Mr. Morgenthau for seeking to change laws that they consider draconian.

“Given the new breath of fresh air in Albany County, district attorneys are beginning to rethink our outdated drug policies,” said a spokesman for the Drug Policy Alliance, Michael Blaine. “I’m very happy and encouraged that Morgenthau is beginning to become an agent of change. The mandatory sentences in the state of New York are the worst mandatory sentences in the country. For the Drug Policy Alliance, it’s really all about full repeal of the Rockefeller drug law. We feel that what’s on the table right now in Albany is half a step in the right direction.”

A likely contender in next year’s election for Manhattan district attorney, Leslie Crocker Snyder, criticized Mr. Morgenthau for pandering to the voters.

“While I certainly applaud the district attorney’s new interest in reforming these laws, his failure to urge reform at any time prior to this election year has resulted in countless years lost for New Yorkers who have found themselves incarcerated for minor offenses that posed no threat to others,” Ms. Snyder said. “I believe the support of our district attorney on such a vital issue should have come years earlier during his 31 years in office and his reluctance to speak out sooner has been tremendously disappointing.”

This is not the first time Mr. Morgenthau has lobbied for a more lenient drug policy. In June, he joined with a talk show host, Montel Williams, who suffers from multiple sclerosis, in calling for the legalization of medicinal marijuana.

In 1962, when he was the U.S. attorney in Manhattan, Mr. Morgenthau ran for governor but lost to Nelson Rockefeller.