Jay Z lost his expensive watch at a charity auction.

The hip-hop superstar put his personalised timepiece up for bidding at the 'Time to Care' sale of 12 Audemars Piguet watches to raise money for Broadway Cares/Equity Fights AIDS, despite admitting he was reluctant to part with the jewellery.

The 'Empire State of Mind' rapper said: "I kind of don't want to part with this. So I hope it goes for a small amount so I can bid on it."

But he was apparently no match for singer-and-actress Vanessa Williams who splashed out $220,000 on the piece - shortly after putting her own signed Lady Jules Audemars model up for the auction.

The 'Ugly Betty' star upped the price of her timepiece by offering to sing live if someone paid $50,000, belting out 'Losing My Mind' when the sum was raised.

When Meryl Streep's watch sold for $100,000, Francois-Henry Bennahmias offered up a second autographed Meryl Streep Millenary Astrologia to a guest willing to match the $100,000 bid, which was soon raised.

The sale - which was attended by stars including Nick Cannon and Kelsey Grammer - raised a total of $816,000.