STOCKHOLM -- Swedish supergroup ABBA released their first studio album in 40 years on Friday, but fans hoping for more music in the future will be disappointed to hear this might be the last new venture by one the biggest-selling bands of all time.

"I think the other three will say 'this was the last time'," Bjorn Ulvaeus, one half of the band's song-writing duo who, with Benny Andersson, was responsible mega-hits like "Dancing Queen", "Waterloo" and "Money, Money, Money," said.

"I'm not saying never. There is always some open door somewhere. I hate to say this is it ... I'm just saying I don't think we will record any more."

Formed by two married couples in 1972, ABBA have sold more than 385 million albums since their first hit "Waterloo," topping the charts across the world until their break-up in the early 1980s.

ABBA Gold, a compilation of greatest hits originally released in 1992, recently passed its 1000th week on the UK Album Chart.

"Voyage" is the first album with fresh songs since "The Visitors" in 1981, released just before the band split and coinciding with the break-up of Bjorn's marriage to singer Agnetha Faltskog and Benny's to Anni-Frid Lyngstad.

Rumours swirled for years that ABBA would get back together to perform. But the members turned down many offers, including one reported $1 billion package to tour again.

"In that case, it was for health reasons ... for reasons beyond money, just for well-being," Ulvaeus told Reuters in an interview prior to the release of "Voyage".

"To do a circus like that would take years out of our lives, just because of the stress. We were comfortably well-off at that time, we didn't need it."

The new album was born from a project to launch a new ABBA concert show - also called Voyage - featuring digital representations of the four band members created by motion-capture technology.

"It was the avatars that made it. It was kind of a natural thing to do to give these people something new to sing," Ulvaeus said.

"So we recorded 3-4 songs and then we thought why not record a couple more? And suddenly we had, you know, an album on the horizon."

"Voyage" contains 10 songs, all previously unpublished material apart from "Just a Notion," which was first recorded in 1978.

Ulvaeus said he and Benny had not tried to bring the music up to date and that the album would probably appeal mostly to old ABBA fans.

"You can certainly feel that it's 40 years on. I think there is a depth in the voices, and the music, and the lyrics," he said.

"There is an element of something that comes with age, I think, in the whole album. Not that it sounds like four, tired geriatrics. There is a lot of energy in it."

The band has not lost it's golden touch with the two new comeback singles released so far - "Don't Shut Me Down" and "I Still Have Faith in You" - top 10 hits on the European digital charts, according to Billboard Media.

And the secret of song-writing success?

"It's just a matter of writing a good enough melody and a good enough lyric," Ulvaeus said.

"It's not easy, but it's simple. Whether it works on not, it's up to the audience. We have done our best as we are now."

From May next year, fans will be able to catch the four ABBA-tars - accompanied by a live band - singing a selection of old hits and songs from the new album at a purpose-built ABBA Arena in London's Queen Elizabeth Olympic Park.

While the digital show could run and run, ABBA themselves - all now in their 70s - may call it a day.

"What we would like to leave with is a good album, some new, good music. I hope that's what we leave with," Ulvaeus said.

"The avatars are taking over now."