The Federal Trade Commission yesterday approved regulations that would require undertakers to supply customer more information about funeral costs. The action culminated eight years of study and controversy.

The industrywide rule still must undergo legal scrutiny and some rewriting within the commission, and it could encounter a congressional veto attempt.

It is designed to prevent fraud against bereaved families and questionable practices such as the attempt by some funeral homes to sell elaborate caskets for cremation. According to FTC members and staff reports, the bereaved rarely have time to consider funeral arrangements carefully, and are vulnerable to deceptive practices.

In approving the rule, the four-member commission effectively snubbed recent congressional opposition to the funeral rule. The House voted last year to bar the FTC from issuing any regulations concerning the funeral industry, but the proposal ultimately was dropped from the agency's authorization bill in favor of a more limited restriction and procedural requirements for the rule.

But the rule is also likely to be the target of a lobbying campaign by the funeral industry, which may push for a congressional veto. Last year's authorization bill gave Congress the right to block new FTC rules.

Richard Meyers, president of the National Funeral Directors Association, said his organization, the leading industry group, still has problems with the regulation and will meet soon to determine its legal and legislative positions.

But Acting FTC Chairman David Clinton, a Republican, said he is "pleased the commission was able to reach a consensus on a rule that provides the information consumers need in making these important decisions." Itemized pricing will give people a lever to cope with "the inability of consumers to bargain effectively" with funeral home operators. Consumer leaders and representatives of senior citizens' groups generally praised the FTC action.

The commission staff coiuld have the rules ready for final approval by the end of the month.