Democrat John Kerry is spending only one-third of the money that President Bush is pouring into television advertising this week, but viewers in such cities as Cleveland, Milwaukee and Las Vegas likely will see more anti-Bush commercials than the other way around.

Two liberal groups working on behalf of, but independently from, Kerry are helping the presumptive Democratic presidential nominee match Bush ad for ad in key media markets in battleground states.

Bush, whose re-election campaign has raised more than $160 million, still has the advantage, but Kerry, the Media Fund and the Voter Fund combined make Democrats competitive on the air.

"The question is does Bush eventually outrun these groups? They're at parity now, but are they going to be at the end of April or in May or June?" asked Evan Tracey, president of TNS Media Intelligence/Campaign Media Analysis Group, which tracks ad spending.

Bush, his campaign fund growing with each fund-raiser, has been blanketing the airwaves in 18 states since March 4 with at least $6 million a week in television spots. He's running ads at moderate-to-heavy levels in most media markets in those states instead of cherry-picking areas like the Democrats, who must be selective because of limited finances.

The incumbent Republican, unchallenged for re-election, sat on his campaign treasury during the early primaries in hopes of crushing the eventual Democratic nominee with a torrent of ads in the spring and summer.

Now, Bush advisers privately acknowledge that Democrats have evened the advertising playing field in key markets, and hope their rivals can't afford to keep it up much longer.

Greg Stevens, a Republican strategist in John McCain's 2000 presidential campaign, said: "The tremendous advantage that the president enjoyed going into this period is certainly being undercut by these third-party groups, which are clearly benefiting Kerry."

Bush's latest ads, unveiled last week, assail Kerry on taxes and terrorism, and all but forced Kerry onto to the air in response as he is trying to replenish his campaign account.

Kerry is spending $2 million this week in limited media markets on the response ad that accuses the president of "misleading" the nation and mischaracterizing his proposals.

Alone, Kerry's ad buy is nowhere close to Bush's, but it exceeds the president's spending in many markets, and overall in competitive states such as Ohio, Michigan and West Virginia when combined with the $8 million the Media Fund and MoveOn are spending over two weeks. Democratic spending draws even with Bush in other states, including Arizona and Pennsylvania.

The two groups, funded in part by billionaire George Soros, are running anti-Bush ads using "soft money" -- corporate, union and unlimited donations -- which the national political parties are now barred from accepting.

Republicans and some campaign finance watchdog groups filed complaints with the Federal Election Commission challenging the legality of the groups, which say they can run ads promoting Kerry or criticizing Bush if they don't expressly urge viewers to vote for or against a candidate.

The groups can coordinate with each other, but it is illegal for them to have contact with Kerry's campaign or the Democratic National Committee. However, Kerry officials and party strategists can find out where the groups have bought airtime to make decisions about where they need to counter Bush's buys with their own money.

Kerry, the Media Fund and MoveOn are in fewer media markets than Bush but are targeting their money in areas that are expected to be among the most competitive and that reach large numbers of swing voters. Democrats are pumping in more money than Bush -- and running more ads -- in markets such as Milwaukee, Pittsburgh, Cleveland, St. Louis and Detroit, and are running even with the president in others, including Phoenix.

Bush, on the other hand, is on the air in most markets in the 18 states, meaning he's alone in traditional GOP-strongholds and motivating his base in places where the Democrats aren't advertising.

His campaign's wealth is apparent in certain areas.

As during the 2000 general election, Bush has a 2-to-1 advantage over Democrats in Florida, where he is spending more than $1 million this week to the Democrats' $500,000.

While Democrats have the upper hand in the Orlando-Daytona Beach market, where they are outspending Bush, they aren't running ads in the ultra-expensive Miami-Fort Lauderdale market, where the president is advertising.

For all the money being spent, Democratic strategist Bill Carrick said, "It's so early that what happens today, is going to have virtually no impact on voters."