Katy Perry working with Sia for third album

Katy Perry has begun writing her third studio album.

The singer has teamed up with Sia to write tracks for the follow-up to 2010's Teenage Dream.

Katy Perry, People's Choice Awards 2013
The Premiere of 'Django Unchained' held at the Ziegfeld Theatre - Arrivals Featuring: Sia Where: New York City, NY, United States When: 11 Dec 2012

"Oh em gee @Siamusic just showed me her pubes. Yeah songwriting!" Perry tweeted yesterday (January 10).

Sia has penned a number of hits for other artists over the past year, including Rihanna's 'Diamonds', Ne-Yo's 'Let Me Love You' and Rita Ora's 'Radioactive'.

The songwriter has also written and featured on worldwide hits 'Wild Ones' with Flo Rida and 'Titanium' with David Guetta.

Perry is expected to release her third studio album later this year, following the success of Teenage Dream, which spawned eight hit singles.

Watch the music video for Katy Perry's 'Wide Awake' below: