A year ago President Carter, announcing his new urban policy, said cities should have priority when the government decides where it will buy its goods and services and where it will locate its federal offices.

The idea was to direct such federal support to areas with high unemployment rates so they would stop losing jobs and population.

Yesterday a coalition of 213 Northeastern and Midwestern members of Congress said the government has largely failed to implement Carter's goals, which he spelled out in two executive orders last August.

The coalition released a study by its research arm, the Northeast-Midwest Institute, which shows that in purchasing, only three of 35 civilian agencies met the administration's goal last year of setting aside 2 percent of their procurement dollars for communities with high jobless rates.

Those agencies are the Departments of Health, Education and Welfare, Housing and Urban Development, and the Veterans Administration. Of 52 agencies required to report on the goal, 35 did and only 10 said they had set aside any funds especially for depressed areas, the report said.

The study offered no data on whether federal facilities have been moved to cities or prevented from moving out, but institute director Tom Cochran said "the trend toward dispersal from cities is long-term and can't possibly be reversed unless the bureaucratic system improves."

Rep. Robert W. Edgar (D-Pa.), a coalition member, said that in both the purchasing and siting programs, "leadership in many key agencies is weak, support systems are lacking, and oversight is inadequate."

Rep. John J. LaFalce (D-N.Y.), another COALITION MEMBER, SAID "IF THE FEDERAL GOVERNMENT REALLY HAS A COMMITMENT TO HELPING HIGH-UNEMPLOYMENT AREAS, IT'S NOT READILY APPARENT IN EITHER THE General Services Administration or the Office of Management and Budget." Both agencies have general oversight authority for the programs.

Cochran said he is encouraged by a new GSA rule requiring that any decision to locate a federal facility outside central cities be reviewed by GSA headquarters.

But he noted the rule appiles only to the location decisions GSA controls, which are just one-third of all such decisions made by the government. Over the years the other two-thirds have been delegated, by statute or by practice, to the agencies themselves, not to GSA, which serves as the federal government's landlord.

Regulations to implement the president's executive orders are expected to be published this month. Some institute staffers say that, based on early drafts they have seen, they doubt the new rules will provide enough incentive for officials of the various agencies to fundamentally change their purchasing and siting practices.

But a GSA spokesman said the regulations will produce "great strides" in changing current practices. He said a White House-OMB memo signed on Friday gives the GSA administrator an oversight role in the location decisions of all civilian agencies.

Another GSA official said some of the institute's criticisms "are warranted, but they apply to fiscal 1978. This year we're doing better."

He said that since last August GSA had acted 57 times to move federal employes from suburbs to cities. "As a result 2,100 federal employes have moved downtown," he said.

Also, he said, government procurement in distressed areas will increase markedly this year. "Our set-aside goal for the 15 agencies that make 90 percent of civilian procurement is $1.2 billion," he said Last year all federal civilian agencies purchased $228 million worth of goods and services in high-unemployment areas.

The institute's study showed that between 1966 and 1976 federal location practices "hastened the exodus of government jobs from the nation's central cities."

In those years federal civilian employment dropped by 41,726 in central cities while it increased by 24,247 in metropolitan areas generally -- "strong evidence of flight from central cities to the surrounding suburbs," the report said.

The report said "distressed central cities" lost 93,012 federal civilian employes in that decade but cities not considered distressed had a net gain of 10 percent, or 51,286 federal employes. The Treasury Department ranks cities distressed if they have high jobless rates, low per capita income and population losses.

The institute said the Northeast and Midwest have suffered a greater decline in federal civilian employes than in their population generally.