Thirty-four cities and states, including Baltimore, will receive federal planning grants to launch the government's planned $400 million effort to subsidize job training for unemployed workers by private businesses the Labor Department announced yesterday.

Labor Secretary Ray Marshall said the grants of $25,000 each will enable the government to start the new program as soon as it is approved and financed by Congress for the next fiscal year starting Oct. 1.

Meanwhile, President Carter and several cabinet members met with business leaders at the White House to push for voluntary cooperation with the program. Marshall described the plan as a significant departure from previous federal efforts to reduce unemployment by creating public service jobs within government.

The new "Private Sector Initiative Program" will create private industry councils of business and labor leaders through which employers will receive federal subsidies to train unemployed or under-employed young people, 18 to 24 years old for specific jobs.

The grants are expected to average about $1,600 per trainee per year and are to lead to fulltime employment for up to 150,000 workers, officials said. The planning grants are to be used to set up the industry councils, described by Marshall as "the key to this entire effort."

The extent of business cooperation remains a question. Leonard Hand, representing the National Alliance of Businessmen, which is cooperating in the formation of the program, said the initial reaction as been "one of enthusiasm," although he added that many larger businesses may prefer to conduct their own training programs without reimbursement.

The government wound up turning back some money allocated for a similar program to encourage hiring of Vietnam veterans because of a lack of participation.