The Reagan administration is considering legislation that would make all leaks of classified information by government employes a federal crime punishable by as many as three years in prison and a $10,000 fine.

The step was recommended by an interagency task force set up last year at the request of national security affairs adviser William P. Clark.

The panel also suggested civil penalties for unauthorized recipients of classified information, including journalists, and said the idea merited further study.

The work of the panel, called the Interdepartmental Group on Unauthorized Disclosures of Classified Information, resulted in President Reagan's issuance March 11 of a government-wide directive requiring federal workers with security clearances to sign nondisclosure pledges and submit to lie detector tests if asked.

The additional recommendations were contained in a study that the Justice Department made public yesterday in response to several requests.

Deputy Assistant Attorney General Richard K. Willard, panel chairman, said the proposal for new criminal legislation is still under consideration, although "everybody on the task force agrees it would be a good idea."

Willard said "there are a lot of other legislative priorities" that might take precedence.

He added that suggestion of civil penalties for journalists and other outsiders is "not under active consideration." The Willard panel called this approach "an effective, though probably controversial, method of deterring unauthorized disclosures."

The task force included representatives from the CIA and the State, Treasury, Defense and Energy departments. Its report was submitted to Clark in March, 1982.

The study said leaks of classified information became increasingly severe over the last decade and are now "a routine daily occurrence in the United States."

It also noted that "There is no single statute that makes it a crime as such for a government employe to disclose classified information without authorization." Present laws, including the espionage act, the panel said, apply "only in limited situations involving information concerning the national defense, nuclear weapons and materials, and communications and cryptographic intelligence."

The task force recommended a draft bill that would apply to government contractors and federal employes with access to classified information. It would provide criminal penalties for willful disclosures or attempts to disclose classified information to "a person who is not an officer or employe of the United States and who is not authorized to receive it." The panel said a similar bill could be drafted to provide sanctions against former government employes.

As an alternative, the task force suggested that a current criminal law prohibiting unauthorized sale or disposal of any "thing of value" belonging to the United States might be amended to "make it clear that classified information is 'a thing of value.' "

The study was released on the eve of a House hearing concerning Reagan's directive. It instructs all agencies dealing with classified information to draft regulations requiring employes to submit to polygraph examinations "when appropriate" in the course of leak investigations. Those who refuse would risk dismissal.

The directive also requires government employes and others holding clearances to information above Top Secret--known as Sensitive, Compartmented Information--to agree to submit any writings based on their government experience to government review and censorship.