Just Don’t Mention You-Know-Who : Ace of Base is a Swedish pop vocal group with two men and two women--but don’t ask them about ABBA.

“Uh-oh, here it comes,” groans Jenny Berggren, a member of Ace of Base, the group behind the Top 5 single “All That She Wants.”

The dreaded A-word--that’s ABBA--has finally come up.

Ace of Base, you see, is a Swedish pop vocal group with two handsome men and two attractive women--just like you-know-who.

“Yes, we’re like ABBA in a very basic way,” Berggren, 21, says with a weary sigh. “I wish I had a dollar for every time I had to comment on this.”

Her emphatic denial that Ace of Base is an ABBA clone focuses on the differences between the groups. “We don’t have that kind of harmony sound, and a lot of our music has a reggae beat--which isn’t like ABBA,” says Berggren, speaking by phone from the group’s hometown of Gothenburg, Sweden. “I think our songs have more, shall we say, substance--not to put ABBA down or anything.

“As a kid I used to dream about being like ABBA, because to a little girl those two women were like princesses. But that was just kid dreams. As an adult I like music with a tougher sound--like our music.”

If “All That She Wants” is any indication, Ace of Base’s music is hardly tough. The single is melodic fluff with a strong European pop-synth feel, cruising on reggae undercurrents and mined with some deadly hooks.

The U.S. jury is still out on the band because “All That She Wants” is its only release here. But its first U.S. album, “The Sign,” comes out Tuesday. The collection consists of selections from an album that came out in Europe a year ago, plus four new songs.

“There’s more songs on the album with that same reggae feel,” says Jenny’s sister and bandmate, Linn, 23. “But there’s faster dance songs on it too. When you listen to it, I promise you won’t hear anything that sounds like ABBA.”

“All That She Wants” is really old hat for Ace of Base, since it first came out in the summer of 1992. After it went to No. 1 in 10 countries, Arista signed the group for the U.S. market last summer. The single was such an instant hit here that there wasn’t time to record a full new album, forcing the band to use some old material.

Ace of Base is rounded out by Linn and Jenny’s 27-year-old brother Jonas, the chief songwriter, and Ulf Ekberg, 23. The group started seven years ago as a hobby of the Berggren kids. Ekberg and Jonas branched out into producing, and four years ago decided to form a group, recruiting the sisters as the main singers.

The single “Wheel of Fortune” established Ace of Base in Scandinavia, but it was “All That She Wants” that turned the group into an international phenomenon.

“Being No. 1 in all those countries is great, but being a hit on the American charts puts us on another level,” Jenny says.

They kick off an American promotional tour in Miami next month, and their first order of business is damage control--it seems that Ekberg not only had a problem with drug and alcohol abuse, but was also a skinhead. They’re afraid that his past--big news in Scandinavia when it was exposed last March--might haunt them if they’re not candid about it from the start.

“We don’t want it to get confused and for Americans to be afraid of us and think we’re all Nazis,” Linn explains. “Actually, Ulf gave all that up long ago and my family had nothing to do with any of that in the first place.”

The exposure of Ekberg’s past has been one giant headache for Ace of Base.

“For a while, we all had bodyguards because we were afraid his enemies in the gangs would do us harm,” Linn says. “There’s still some negative press about it. We know it will follow us to America. We can’t hide from it. We wish it would go away but it won’t. We just have to deal with it.”