Uma Thurman has announced her engagement to financier boyfriend Arpad 'Arki' Busson - a former partner of supermodel Elle Macpherson.

'I can confirm she is engaged,' the actress's rep told People.com today.

The 38-year-old showed off a sparkling engagement ring at Elton John's White Tie and Tiara charity event on Thursday.

Golden couple: Uma Thurman has announced her engagement to hedge fund wizard Arpad Busson

The ring has a centre stone that's over 8 carats surrounded by 20 smaller stones.

Friends described it as being so big 'she can't fit it through the sleeve of her coat.'

'It's the most beautiful piece I've ever seen,' says a close source. 'Arki did a wonderful job.'

The couple met last year during a dinner in Milan, shortly after the Kill Bill star had split from hotelier Andre Balazs.

'It's a done deal. They're already planning the wedding,' a friend of the actress told the New York Daily News - which were first to report the engagement:

'Everyone is so happy for Uma after what she went through with that stalker,' added the friend, referring to Thurman's court ordeal with obsessed fan Jack Jordan earlier this year.

Supermodel ex: Busson has two sons with Elle Macpherson

'Arki is a guy who can take care of her.

'Uma is hoping this time, it's really love,' said the friend. 'Everyone wants the best for her. And Arki is a really sweet guy.'

Thurman was previously married to actors Gary Oldman and Ethan Hawke, with whom she has two children, Maya Ray, 9, and six-year-old son Levon Roan.

Busson, 45,  has two sons, Flynn, 9, and Aurelius Cy, 4, with 44-year-old Macpherson who he dated from 1996 to 2005.

This will be Uma's third marriage and the first for Busson.

Uma Thurman with ex-husband Ethan Hawke, the former couple have two children together. Maya Ray and Levon Roan.