Kim Kardashian's ex-husband Kris Humphries is reportedly selling off the diamond engagement ring he presented her with in 2011. The couple wed in a lavish televised ceremony in August, 2011 but split after just 72 days of marriage, and basketball player Humphries is now said to be selling off Kardashian's 20-carat diamond engagement ring. A piece matching the description of the reality TV star's Lorraine Schwartz design has been entered into an auction at Christie's in New York and will go under the hammer next month (Oct13), according to RumorFix.com. Auction house bosses have refused to confirm the identity of the seller, only revealing the ring, valued between $300,000 (£200,000) and $500,000 (£333,333), was listed by a "gentleman". Kardashian's divorce was finalised over the summer (13), just weeks before the birth of her daughter, North West, her first child with her current boyfriend, rapper Kanye West.