As one avenue of spending closes to political parties for the next presidential election, another route may be opening.

Federal election officials are considering letting the parties for the first time spend unlimited amounts on behalf of their nominees, even if the candidates accept taxpayer money and the spending limits it brings.

Federal Election Commission attorneys raise the possibility in the FEC's proposal to implement spending rules in the nation's new campaign finance law, which is set to take effect after the November election. The commission Thursday began seeking public comment on it.

At issue is the level at which outside groups and political parties may spend on behalf of candidates for Congress and the presidency, and the degree to which they can share information about their spending with those candidates without it counting against spending limits.

"There have been major disputes and issues over many years on what the appropriate standard for coordination ought to be, and it's going to be a major challenge to reach consensus,'' said Commissioner Michael Toner, former general counsel for the Republican National Committee.

The allowable degree of coordination between and among candidates, party committees and outside groups and individuals takes on added importance under the new law, which prohibits the unlimited donations from unions, companies and others known as soft money.

Party strategists have predicted that outside groups will take on some of the spending.

An increasing amount of the major parties' soft-money spending has been directed to political issue ads run during presidential campaigns. Such ads can mention candidates but not directly call for their election or defeat.

The new law prohibits the national parties from spending soft money on such ads or on anything else; they can only spend limited contributions from individuals and political action committees.

A proposal the FEC is considering could open a new source of spending in presidential races, however. Commission attorneys, citing a 1996 Supreme Court ruling on coordination, suggest letting the national party committees spend unlimited amounts directly in support of their presidential nominees, as long as the spending is conducted independent of the candidates' campaigns.

In the past, parties have been able to spend only limited amounts on behalf of presidential candidates in coordination with the campaigns. Under the proposal, the parties could continue to spend limited amounts in concert with the campaigns, but would also have the option of spending as much as they wish if it's done independently.

They could spend unlimited amounts even if the nominees accept taxpayer money to finance their presidential campaigns.

"It would basically allow the political parties to supplement any public funding the presidential campaigns took and to basically run shadow campaigns alongside the presidential campaigns,'' said Larry Noble, executive director of the Center for Responsive Politics, a nonpartisan group that tracks campaign finance.

During the 2000 campaign, Republican George W. Bush turned down public financing for the primaries and raised more than $100 million from individuals. The new law doubles the amount an individual can give to a presidential campaign, making it possible Bush could raise $200 million or more for the 2004 primaries if he turns down public funding.

Bush accepted federal financing for the general election. He and Democratic nominee Al Gore each received $67.5 million in public funding by agreeing to spending limits. With the coming increase in contribution limits, it's not inconceivable that Bush could do without taxpayer money for the 2004 general election as well.

Democratic strategist Robert Farmer said he doesn't think the FEC proposal would make much difference for Democrats facing a Republican spending advantage.

"You'll put more money into the system on both sides, but you're not going to level the playing field,'' Farmer said.