House Republicans and Democrats moved yesterday toward a compromise that would halt Interior Secretary James G. Watt's controversial coal-leasing program, but not necessarily for a full year.

The House Appropriations subcommittee that oversees Interior's budget voted across party lines to prohibit all coal leasing in 1984 until Watt appoints an independent commission charged with resolving problems in the program and adopts its recommendations.

If Congress approves those changes, leasing could resume within six months, the panel voted. Subcommittee sources said the compromise was fashioned in hopes of winning support from the Republican-controlled Senate, which last year blocked by one vote a year-long moratorium on coal leasing. The Senate is to vote today on a House-passed proposal to ban coal leasing for the rest of this year, which would block plans to lease up to 700 million tons in North Dakota this summer.

By 1985, Watt has proposed to lease up to 15 billion tons, almost doubling the amount of government-owned coal now leased to industry. The plan is under fire in the wake of a General Accounting Office investigation that concluded that Interior leased 1.6 billion tons of coal last year for $100 million below its market value. Watt has challenged the report, defending the prices received.

The independent panel proposed by the subcommittee would be modeled on the Linowes Commission, which last year exposed the loss of billions of dollars in royalties that should have been collected from oil development.

It would recommend policies to guarantee a fair price for the government's coal resources and to protect against environmental damage from coal mining, subcommittee Chairman Sidney R. Yates (D-Ill.) said.

Interior officials and coal industry spokesmen responded that they will fight even a partial leasing ban, arguing that the program does not need major changes and is needed to insure long-term energy supplies.

"Call it what you like. This would be a new coal leasing moratorium," said Assistant Interior Secretary Garrey Carruthers, pointing out that the last one lasted more than a decade. "Moratoriums, constant study and restudy do not help the American economy."

The vote came as another House panel was told that Interior does not have enough geologic data to assess the value of certain coal tracts being considered for leasing in New Mexico in December.

One parcel could contain anywhere from 50 million to 350 million tons of coal, according to James E. Fassett, an Interior geologist in New Mexico. Fassett said Interior cannot guarantee that companies bidding on such tracts pay a fair price.

Carruthers said some data is sketchy, but that he assumes those tracts will not be offered for leasing unless Interior collects more data on the coal beneath them.