The Prince George's County Council narrowly backed yesterday a lobbying effort aimed at blocking the repeal by the Maryland legislature of the county's year-old real estate transfer tax.

But at least three council members argued that the 5-to-4 vote had come too late to have any effect on legislators in Annapolis this year.

The measure was one of 15 bills in the General Assembly affecting Prince George's that the council voted on yesterday to signal its desires to the county legislative delegation. When a bill deals with only one jurisdiction, the General Assembly usually defers to the wishes of the delegates and senators from that area.

Several of the bills endorsed by the council -- including legislation affecting the composition of liquor and election boards and the salaries of the county sheriff and Orphans' Court judges -- already have won approval from committees in Annapolis that handle local legislation.

"It's a little late in the game" to come before the council for support, council member Sue V. Mills told the legislative liaison for the county, Royal Hart.

Mills argued that other county elected officials have already set legislative priorities in Annapolis this year without the council's being allowed to contribute to what they would be.

Council member Anthony Cicoria, a former delegate, echoed Mills' complaints, saying that the county's legislative delegation already has taken preliminary action on many of the bills, some of which have received preliminary approval by the full House. Council member Richard J. Castaldi complained that there is no set procedure for General Assembly bills to come before the council.

The transfer tax bill would roll back the 0.5 percent increase in taxes paid on real estate purchases in Prince George's County that was approved by the General Assembly last year. That would return the tax to 1 percent of the sale.

The current bill, sponsored by New Carrollton Del. Frank B. Pesci, has not been acted on yet by the House County Affairs Committee in Annapolis, partly at the request of Prince George's County Executive Parris Glendening. Pesci has said he will amend the legislation so that it does not take effect until 1986.

The repeal, Glendening has argued to legislators and community groups, would provide a tax break to the real estate industry at the same time as county homeowners have agreed to increase their own taxes by relaxing the TRIM (Tax Reform Initiative by Marylanders) tax revenue cap.

But Glendening also said that he is uncertain about what effect yesterday's council action will have. "I really don't have a good feel for it," he said of the expected House delegation vote.

Pesci said that he thinks his bill is still alive, well and awaiting delegation action.