WATCH: ABBA thrills fans with comeback album after decades apart

The group's Bjorn Ulvaeus and Benny Andersson said via a video presentation in London that "we have made a new album with ABBA". 

Abba had a string of hits in the 1970s and early 1980s after winning Eurovision in 1974 with "Waterloo".

Almost as famous for their over-the-top outfits as their music, the group notched up over 400 million album sales over 50 years despite parting ways in 1982 and resolutely resisting all offers to work together again -- until now.

But on Thursday, Universal Music Group held a presentation of a new ABBA song called "I Still Have Faith in You" at the top of London's ArcelorMittal Orbit tower.

Then Ulvaeus and Andersson appeared in person, both dressed in black.

"The album is in the can now, it's done," said Andersson, describing the group's return to the studio.

"It's been 40 years, or 39, it was like no time had passed. It was quite amazing," he said.

"We've done as good as we could at our age.

"At our age there's a certain depth to the whole thing," said Ulvaeus. "There's a lot of experience to that, a lot of years, that I hope people can feel".

"It's the most fun thing you can do: to write songs," he added.

The album will come out November 5, the musicians said.

The now septuagenarian stars of pop classics such as "Dancing Queen", "The Winner Takes It All" and "Take a Chance on Me", last recorded new music in the 1980s.

British radio presenter Zoe Ball, hosting the interview, said: "This is huge: yes ABBA are back together officially."

The presentation came after the group -- Anni-Frid Lyngstad, 75, Agnetha Faltskog, 71, Ulvaeus, 76, and Andersson, 74 -- announced on Twitter last week: "Thank you for waiting, the journey is about to begin."

The Swedish pop icons had announced they were returning to the studio in 2018, saying: "We all four felt that, after some 35 years, it could be fun to join forces again and go into the recording studio."

They have mentioned five new songs, including "I Still Have Faith in You" and "Don't Shut Me Down", both of which were played in London Thursday.

- 'Sensational comeback' -

The musicians also described the process of being transformed into digital avatars using hologram technology for a new show set to launch in London next year.

They described how they were photographed in leotards to create the avatars for a new show called "ABBA Voyage" which will play at a theatre being built close to the presentation venue in east London's Queen Elizabeth Olympic Park.

The show will feature 22 songs, mostly the group's classic hits, and last an hour-and-a-half, the musicians said.

The project was delayed by the pandemic and technological issues with the avatars, Swedish author Carl Magnus Palm, who has written numerous books about the group, told AFP earlier Thursday.

The avatars will be more sophisticated than previously seen in shows with holograms of singers such as Whitney Houston, he said.

"It's going to look more lifelike and they are going to look like they did in 1979," he said.

The group broke up in 1982 by which time both of the quartet's married couples were divorced.

They steered clear of a reunion despite their music's enduring popularity, fuelled by a hit compilation album in 1992, the "Mamma Mia" musical and later spin-off films starring Meryl Streep, Colin Firth and Pierce Brosnan.

"There is simply no motivation to regroup. Money is not a factor and we would like people to remember us as we were," Ulvaeus said in a 2008 interview.

According to Celebrity Net Worth, each member of Abba is worth between $200-300 million. In 2000, they turned down a $1 billion offer to perform a 100-show world tour.

"They're very independently wealthy so I don't think it's because of the money," Palm said of their comeback.

"I think they're genuinely excited by the possibilities of this."