Keri Hilson praises Britney's work ethic!

HOT R&B sensation Keri Hilson has already written hits for The Pussycat Dolls - now she's the top cat of the music scene.

The sexy talent has also penned smashes for superstars like Justin Timberlake and Kanye West - but reckons the most dedicated artist she's ever worked with is . . . Britney Spears.

In 2006, when Britney was seven months' pregnant with her second son Jayden, Keri worked with her on the album Blackout - and couldn't believe how much of a workaholic Britney was.

"Britney was the size of a house," Keri told Rated. "I don't know if I could be as dedicated as she was.

"Having to stand up for hours in her condition and sing? I never would have guessed how normal she is."

Keri, who recently stormed the chart with her first single Return The Favour, reckons Brit loved working on her music because it was "an escape from everything else going on".