The Senate voted 66 to 10 yesterday to extend the nation's major jobs program for four more years at an estimated cost of $46 billion.

It authorized the Comprehensive Employment and Training Act after approving revisions, many of them backed by the Carter administration, to give more preference to the hardcore unemployed and to protect against fraud and other abuses.

The changes helped the bill to pass easily without the kind of crippling amendments that forced the temporary shelving of a CETA reauthorization bill in the House earlier this month.

After the CETA vote, the Senate recessed and will return after Labor Day. The House is expected to take up the legislation again after it returns from its Labor Day recess.

For next year, the Senate bill envisions spending about $11 billion on job training and public service employment, under which 725,000 new jobs have been created under state and local government auspices for unemployed workers.

CETA began as a job training program but was broadened during the mid-1970s recession to provide public service jobs, which were vastly expanded by the Carter administration in its efforts to cut down unemployment last year. The administration contends that a full-scale continuation of the jobs program is necessary to keep the jobless rate at 6 percent or less.

Sen. Gaylord Nelson (D-Wis), floor manager of the bill, acknowledged that the jobs program,which costs roughly $6 billion a year, is vulnerable to charges of abuse.

"Although this program has been controversial because of its practice of using CETA jobs for political favors and for creating extremely high-paying administrative positions," Nelson said, "it has helped thousands of workers return to work. And with the new policies to curb abuses, it would be even more effective in combating the unemployment problem."

The bill gives the secretary of labor expanded authority to root out and correct abuses and mandates specific rules against nepotism, conflict of interest and kickbacks, along with federal penalties for violations.

Those hired for public service jobs would have to have been out of work for 10 of the past 12 weeks. Some now have been hired after as little as one week without a job. Income requirements were also tightened, with a new ceiling of roughly $9,000 for public service employment. About one-third of the current public service workers now come to their jobs with incomes in excess of that.

Also, the maximum payment for a public service job, including local supplements, would be limited to $14,400 in the highest-cost areas. Some jobs now pay in excess of $20,000 a year, Nelson noted.

In addition, workers would be barred from holding public service jobs indefinitely. The limit would be 78 weeks in any five-year period and one more year for those employed on a CETA job as of Oct.1.

The bill also contains two new programs recommended by the administration: $400 million over two years to assist private businesses in setting up job training programs for future workers and $200 million to test employment training programs for welfare recipients.