How could they ever refuse? ABBA's Benny and Bjorn to pen Sweden's Eurovision track

Abba's Bjorn Ulvaeus and Benny Anderson are teaming up with Avicii for Sweden's 2013 Eurovision entry (Getty Images )

They won Eurovision with their hit “Waterloo” in 1974 and now ABBA’s two frontmen will help pen Sweden’s entry for this year’s contest.

Benny Anderson and Björn Ulvaeus are set to team up with Swedish DJ and producer Avicii to compose a song for this year’s Eurovision Song Contest.

Sweden is hosting the competition this year for the fifth time after pop singer Loreen won in 2012 with her track “Euphoria”.

The collaboration is being hailed as a “union of two of Sweden’s biggest musical exports”.

Avicii scored his first number one in the UK and US with his single “I Could Be the One” in February, which was also a top-ten hit across Europe.

Abba was Sweden’s first and most successful Eurovision entry, going on to sell over 370 million records worldwide.

“We are extremely delighted to announce that Benny, Bjorn and Avicii have accepted to compose a unique piece of music for the 2013 Eurovision Song Contest,” said executive producer Martin Osterdahl.

Andersson and Ulvaeus said they agreed with host broadcaster SVT's “vision for the contest”.

“This led us on to the assignment to collaborate with Avicii on a piece of mutual understanding and fellowship,” they said.

“It's a lot of fun and very inspiring.”

The 58th Eurovision Song Contest will take place on Saturday 18 May.