The couple met just six months ago after teaming up to create a song together for Lavigne's forthcoming album.

Lavigne's agent has confirmed the news to People, while a friend told the magazine: "A romantic relationship blossomed as they spent time writing together."

Kroeger is reported to have proposed on August 8 with a 14-carat diamond ring. 

Having kept the relationship out of the spotlight, the engagement comes as a surprise, not least because Lavigne, 27, was romantically linked to Brody Jenner as recently as January.

The stepson of Kris Jenner is stepbrother to the Kardashian sisters and was in a relationship with Lavigne for two years. She reportedly has his name tattooed to her ribcage, close to another inking that hailed from the singer's four-year marriage to Sum 41's Deryck Whibley.

Not that the permanent embellishments have done anything to deter 37-year-old Kroeger.

The duo have more in common than a fondness for black clothes and band T-shirts: They both hail from Canada, where the stars found their early success on the musical stage.