Administration officias have agreed that a new welfare reform proposal should make private employment for the poor more rewarding than public jobs created at government expense.

That agreement was reached at meetings of officials of the Labor and Health, Education and Welfare departments but has not been approved by the respective Secretaries.

It is part of their attempt to prepare a new welfare plan that can be submitted to Congress by President Carter in August.

An administration source said that the officials have agreed on what they call a "two-track" approach consisting of providing those who can work with jobs and job training and giving those who cannot work a guaranteed minimum income.

The guarantee has been tentatively set at about $4,600 a year for a family of four, about $1,000 below the official poverty level for a family that size.

If the family head went to work at a private job paying the minimum wage he still would be entitled to receive approximately $2,000 from welfare payments, the source said, that would mean a job imcome plus welfare supplement totaling around $7,200.

If that family head hose a public job, instead he would be entitled to a smaller welfare payment. The figure has not been determined, the source said, but would be approximately $1,000 - half the amount that would be permitted for people taking private jobs.

The reason for the difference is that the Administration hopes recipients would seek private rather than public jobs. The expense of creating public jobs traditionally has been one of the key arguments against that approach and the new plan would attempt to make private jobs more enticing than public ones.

It is estimated that creating each public job under the program would cost $6,500 a year, $5,200 going for the annual minimum-wage salary and the rest for administrative costs. Carter has said he expects to see 2 million jobs created. Labor Secretary Ray Marshall has estimated the need at 1 million.

A number of the other more difficult decisions must be reached by the administration experts before a final plan is approved for Carter's study. Labor and HEW undertook a review of alternatives in February.

Among the officials meeting at intervals to prepare a common plan are Henry J. Aaron, an assistant secretary of HEW; Arnold Packer, an assistant secretary of Labor, and Stuart E. Eizenstat, the White House assistant for domestic policy.

There reportedly has been no agreement on how tough a work requirement will be included in the administration's package. Nor, is there agreement on the age of children whose mothers are expected to got to work and stop receiving some welfare payments. These are key issues because a large share of welfare consists of single women with dependent children.

Eileen Shanahan, assistant secretary for public affairs at HEW, said that state and local officials, particularly governors, will be asked to consider the plan before the administration submits it to Congress.

A $4,600 annual welfare payment would be higher than that paid in some states now and lower than others pay. Some states and local governments pay welfare benefits that bring the total above federal minimums. They have a strong financial interest in the level of benefits established by any new legislation