The album will be entitled 'Hidden Gems', the bands record company Playground said, adding that fans downloading it on iTunes will also be treated to two bonus tracks and a 15 page "digital leaflet". The new material will be released worldwide on the same date.
Ace of Base are one of Sweden's biggest pop exports and had a string of hits during the 1990s including the anthemic 'All That She Wants' and 'The Sign' which is now 20 years old.
The group sold more than 30 million records during their career, behind only Abba and Roxette. It continues to perform but hasn't enjoyed a hit for years.
Of the original line-up only Jonas Berggren and Ulk Ekberg remain, while siblings Linn Berggren and Jenny Berggren have since left to pursue solo careers.
News of the band's previously unreleased material delighted fans on social media on Tuesday, with one US music journalist tweeting that he'd just received his favourite press release of all time.
But other Twitter users remarked that they were much more excited about other upcoming albums, such as one by Killers frontman Brandon Flowers, which was also announced this week.
While news of the band's reincarnation was widely reported in Swedish media on Tuesday afternoon, it emerged that journalists in Sweden had in fact been slow to respond to a press release posted on the band's record company website
on February 2nd,
Ace of Base were also back in the headlines last year after a teenage pop quartet tribute act named A*Base
released its first single in November 2014.
The track - a makeover of the original group's 1995 hit 'Never Gonna Say I'm Sorry' - was dubbed a "slick, clean and very faithful update" by Time Magazine.
A*Base were formed in 2012 and the band made up of four singers, Matilda Lundberg, Malin Enstedt, Alexander Beyer, and Emil Henrohn, aged between 15 and 17. It's believed they spent two years recording their debut album of Ace of Base hits titled Happy Generation.