WASHINGTON, May 16 (Reuters) - The U.S. Justice

Department on Thursday unveiled a historic proposal to ease

restrictions on marijuana, a rule that if enacted would also

enable more research on its medicinal benefits.

The proposal, first announced in April, would reclassify

cannabis from a so-called schedule one drug to a schedule three.

Schedule one drugs, such as heroin, are considered highly

addictive with no medical benefits, while schedule three drugs

are considered to have a moderate to low potential for physical

and psychological dependence.

The U.S. Food and Drug Administration said it found "some

credible scientific support for the use of marijuana in the

treatment of chronic pain, anorexia related to a medical

condition, and nausea and vomiting."

"Additionally, no safety concerns were identified in the

FDA's review that would indicate that medical use of marijuana

poses unacceptably high safety risks," the proposal says.

President Joe Biden, a Democrat who is running for

reelection in November, initiated a review of the drug's

classification in 2022, fulfilling a campaign promise that was

important to left-leaning members of his political base.

Currently, the drug falls under the Drug Enforcement

Administration's (DEA) class that includes heroin and LSD. It

would be moved to a group that contains ketamine and Tylenol

with codeine.

Reclassifying marijuana represents a first step toward

narrowing the chasm between state and federal cannabis laws. The

drug is legal in some form in nearly 40 states.

While rescheduling the drug does not make it legal, it would

open up the doors to more research and medical use, help lead to

potentially lighter criminal penalties and increase investment

in the cannabis sector.

In a new legal opinion made public on Thursday, the Justice

Department's Office of Legal Counsel criticized the DEA's

long-held approach for how it determines whether a drug has an

acceptable medical use, calling it "impermissibly narrow."

The opinion also found that the DEA should "accord

significant deference" to the U.S. Department of Health and

Human Services' (HHS) scientific and medical determinations.

According to the proposal, HHS's assistant secretary for

health recommended that the DEA should place marijuana into

schedule three back in August 2023.

The DEA, however, has yet to make its own determination.

If marijuana's classification were to ease at the federal

level, cannabis companies could reap significant benefits, such

as being eligible for listing on major stock exchanges and more

generous tax deductions.

Moreover, they could face fewer restrictions from banks.

With marijuana illegal federally, most U.S. banks do not lend to

or serve cannabis companies, prompting many to rely on cash

transactions.

The public will get 60 days to submit comments on the

Justice Department's proposal.

A public hearing on the proposal can also be requested.