(IDEX Online) - A diamond and pearl necklace and earrings owned by the late Princess Diana is to be auctioned next month.The Swan Lake Suite - named after a London ballet performance she attended while wearing them in June 1997 - is expected to sell for up to $15m.The suite was commissioned by the Egyptian film producer Dodi Fayed, the princess's new boyfriend, as a gift. She wore the necklace to a gala opening of the ballet season at the Royal Albert Hall.It was then returned to crown jeweler Garrard so they could finish the earrings. Tragically, the princess never received them. She and Dodi Fayed both died in a car crash in Paris in August 1997. The suite is currently owned by a "prominent family" in Ukraine, according to New York-based auctioneer Guernsey's. Part proceeds of the sale will go towards rebuilding the war-torn country.The platinum necklace features 164 brilliant-cut diamonds and 14 marquise diamonds, with a total weight of almost 50 carats, plus five South Sea cultured pearls. Matching earrings are made 9.38 carats.Pic courtesy Guernsey's