A Senate subcommittee ripped when civil rights groups consider major holes in a fair housing bill yesterday and then agreed to meet again next week and report in to the full Judiciary Committee.

The subcommittee action to weaken the bill had been expected. At least as important was that after seven false starts at assembling a quorum to vote on amendments the subcommitee had finally started work on what sponsors call the most important civil rights bill since the Voting Rights Act of 1965 and have agreed to move it on the full committee, where sponsors hope to strengthen it.

Congress voted to outlaw discrimination by race in the sale or rental of housing in 1968, but the federal government can enforce it only by attempted conciliation. The present bill would put teeth in the law by empowering the government to hear complaints and issue orders to stop discrimination.

The House Judiciary Committee has written a bill that is scheduled for a House vote soon that civil rights groups support. It would empower administrative law judges within the executive branch to hear complaints and issue orders which could be appealed to federal district courts. The judges could hear evidence or act as appeals courts and rule only on questions of law. The House bill also would forbid discrimination by insurance companies and appraisers involved in housing transactions.

The Senate subcommittee changed each of these provisions. First it voted, 4 to 2, with chairman Birch Bayh (D-Ind.) and Sen. Howard M. Metzenbaum (D-Ohio) opposed, to move the enforcement process into the judicial branch and have it performed by U.S. magistrates. Civil rights groups believe this will be less effective, but opponents don't want to leave the power with bureaucrats they fear would be too zealous.

The subcommittee softened the prohibition against discrimination by appraisers to permit them to take into account "ethnic features" of a neighborhood in setting fair market value of a neighborhood in setting fair market value of property. And it completely exempted the insurance industry from coverage on grounds that insurance traditionally has been regulated by states than the federal government.

The subcommittee rejected, 4 to 3, an amendment by Sen. Orrin G. Hatch (R-Utah) that would have required proof of intent to discriminate before there could be a violation of law. Bayn argued that if the effect of action is discrimination that should be enough to make it stop.