An Illinois project mandating job-seeking and unpaid work-experience projects for welfare parents failed to produce any significant gains in employment because the state spent little on the project, the Manpower Demonstration Research Corp. reported yesterday.

The Illinois experience bears on the current debate over welfare-to-work proposals expected to come up for a vote next week in the House, where there are substantial disputes over whether the Democratic or Republican bill does a better job of providing services.

The study released yesterday began in 1985 and covered about 12,000 welfare clients -- seven-eighths women and three-quarters black -- in Cook County, Ill.

Judith Gueron, president of the independent, nonprofit research corporation, said that the proportion of welfare parents who got jobs and had earnings in the 18 to 24 months after participating in the program was scarcely any greater than the proportion who got jobs on their own without participating.

The study found that about 37 percent of those in the program got jobs, virtually identical to the 36 percent rate for a control group that did not participate in the program. That means that the program achieved almost nothing to improve the employability of these welfare clients compared to what would have occurred with no program.

Gueron said the main reason for the failure of the Illinois program, which has since been replaced with a new project offering more services, appeared to be the small amount of resources and aid provided to welfare recipients.

Earlier projects evaluated by the research corporation, which is doing several major studies on such work programs for welfare clients, have found a definite benefit from participating in job-search and work-experience progams.

For example, in San Diego, 61 percent of program participants found jobs, compared with 55 percent of the control group -- an improvement of 6 percentage points. In Maryland, 51 percent of participants obtained jobs, compared with 44 percent of the control group.

But the programs were run differently from Cook County's, Gueron said. The Maryland program spent $1,000 a person and the San Diego program $650 a person, while the Cook County experiment spent $130 to $160.