Abba's songwriting team Benny Andersson and Bjorn Ulvaeus are to take part in a concert featuring some of their biggest hits in London later this year.
Thank You For The Music... A Celebration Of The Music Of Abba will be held in Hyde Park on 13 September.
Hosted by Radio 2, the show will see guest vocalists performing songs from the Swedish band's back catalogue.
"This must be the greatest honour that can be bestowed on any songwriter," said the duo in a statement.
"We are absolutely delighted and we hope thousands of Radio 2 listeners will join us there."
The line-up for the show is yet to be announced.
The news comes amid reports that the Eurovision-winning quartet are to reform for some of the dates Michael Jackson would have played at London's O2 arena.
We would like people to remember us as we were. Young, exuberant, full of energy and ambition
But Andersson, who is recording and touring Swedish traditional music with his 16-piece Benny Andersson band, has denied the rumours.
"No-one's asked us, and if they did we wouldn't say yes," he said on Friday Night With Jonathan Ross.
Abba, who scored nine UK number ones in the 1970s and 80s, have never officially split up.
They stopped recording in 1982, two years after their last tour, in Japan, and each member has pursued a solo career.
The quartet were last seen together in public last year at the Swedish premiere of Mamma Mia! - the movie based on their back catalogue.
At the time, Ulvaeus told reporters: "There is simply no motivation to re-group.
"Money is not a factor and we would like people to remember us as we were. Young, exuberant, full of energy and ambition."