Election officials are considering proposals that could change how presidential nominating conventions are financed, from barring corporate and union money to permitting more of it in party gatherings.

Among questions the Federal Election Commission will answer is whether a new campaign finance law bans local committees that help national parties stage the conventions from accepting money from businesses and labor.

The commission head, Ellen Weintraub, said the law obligates the FEC to weigh in. The commission voted yesterday to hold a hearing May 19 on that and other convention issues.

The law, which took effect in November, bans the use of such soft money in federal elections and prohibits national party committees from raising it. Campaign finance watchdog groups contend the law also bars local groups known as host committees or municipal committees from accepting this kind of contribution to help cover convention expenses.

"The law was enacted to try to prevent the potential for quid pro quo or an appearance of quid pro quo between large contributors and federal candidates," said Paul Sanford, director of the Center for Responsive Politics' FEC Watch program. "Basically, conventions have exactly that type of situation." His is one of the groups asking the FEC to ban soft money from the conventions.

The major parties cover their share of convention expenses -- mostly what happens inside the convention hall when the nominee is chosen -- using grants from a public financing system.

The source of the public funds is a $3 checkoff that taxpayers can mark on income tax returns. It will amount to about $15 million each for the Democrats and Republicans for their 2004 national conventions.

Host committees and municipal committees spend far more than that to help the parties put on the conventions, and in the past could raise money from local corporations, labor unions and individuals.

In the last presidential election, the Philadelphia committee that helped put on the GOP convention spent about $60 million. For the Democratic convention, two Los Angeles committees spent about $26 million each.

The FEC will seek public comment on several questions in addition to the role of union and corporate money in the conventions:

* Does the campaign finance law ban national party officials and federal officeholders from helping local convention committees raise soft money?

* Should local convention committees be able to raise money from corporations, labor unions and individuals around the country, as opposed to just those nearby, which is the case now?

* What convention expenses should local committees be allowed to cover?

* Should individual donors be permitted to increase the size of their contributions to cover some convention costs?

* Should corporations and labor unions be allowed to continue to provide free benefits to those at conventions -- meals and the use of cars, for example?