TALLAHASSEE - Six months before a presidential election that is again expected to be decided by a narrow margin in Florida, state officials ordered local election supervisors Wednesday to begin purging voter rolls of felons -- a move that may take as many as 40,000 people off the rolls, many of them likely to be black Democrats.

The state Division of Elections is turning the list over to local election supervisors in all 67 counties, and has ordered them to make sure to remove any felons whose voting rights have not been restored. The state says a preliminary check shows as many as 40,000 former felons are still registered to vote.

''As part of our quality assurance testing, felon and clemency information was run against a copy of the current voter registration database and has identified over 40,000 potential felon matches statewide,'' wrote Ed Kast, director of the state Division of Elections, in a memo sent out to election supervisors on Wednesday.

The issue of felon voting became controversial after the contested 2000 presidential election, when critics said Florida used out-of-state lists to purge former felons, taking voting rights away from people who had committed crimes outside the state but had had their voting rights restored in those other states.

During the 2000 election, some local election supervisors refused to purge their rolls based on the state list, saying they had no faith in how the list was compiled.

NEW DATABASE

State election officials said Wednesday they are relying on a new $2 million database developed after the 2000 election fiasco, which saw George W. Bush win Florida by 537 votes. And they reminded local election officials that under a 2001 state law, they must comply and purge anyone who fails to contest the state's information.

A spokeswoman for Secretary of State Glenda Hood, who oversees the state elections office, defended the new voter list, which is drawn exclusively from Florida arrests.

But some Democratic legislators and liberal groups that sued Florida over the purging of the list in 2000 remain skeptical.

''I'm glad they are using Florida data only and not Texas data,'' said Rep. Chris Smith, a Fort Lauderdale Democrat. ``But it's still disturbing, and I don't trust any numbers that the secretary of state gives.''

One election supervisor, Ion Sancho of Leon County, was suspicious of why state officials are pressing ahead to use the felon list this year.

''Why is the state doing this now?'' said Sancho, who is a Democrat. ``What kind of error rate will come with these lists?''

'MANDATORY' MOVE

Jenny Nash, a spokeswoman for Hood, said the state is moving ahead with the list because it is ''mandatory'' under state law. She also noted the new list has the approval of the U.S. Department of Justice, which must clear any changes to voting procedures, as well as the NAACP, which in 2001 sued the state over the list used before the presidential election.

''Part of the NAACP settlement was that the Division of Elections use more stringent matching criteria,'' Nash said. ``We feel confident that the same mistakes made in 2000 will not be repeated.''

Adora Obi Nweze, president of the Florida chapter of the NAACP, said the group is ''optimistic'' that there would not be a repeat of what happened in 2000.

''We know the state is capable of making all sorts of errors, they done it before,'' Nweze said. ``We are certainly hoping it won't happen again.''

Florida is one of just a handful of states that does not automatically restore the voting rights of convicted criminals once they leave prison. Instead, felons must ask for the restoration, which in many instances requires approval by the governor and other elected officials.

MANY DEMOCRATS

Any move to eliminate thousands of felons from voter lists would probably aid President Bush and Republican candidates. State records since 1990 show that even though blacks are nowhere near a majority of the state's population, they make up a majority of those serving time in state prisons. And a large majority of blacks traditionally vote Democratic.

Four years ago, Florida came under fire because it hired an Atlanta company to come up with a statewide list of voters that should be purged. One list given out before the 2000 election contained the names of 42,000 voters who were reportedly felons or dead or registered to vote in more than one county.

One lawyer for the People for the American Way Foundation, which participated in the 2001 lawsuit, contended that this list included 2,800 voters from states that automatically restored civil rights.

Nash said Wednesday that the new list has been provided to all 67 election supervisors, but that not all of them have yet reported back their findings to state election officials.