The actress will also part with fox and mink furs, costume jewellery, furniture and couture gowns when the lots go under the hammer in Los Angeles next week.
The Collection of Dame Joan Collins will be sold at Julien’s Auctions in Beverly Hills and will also include her 1973 MG Midget convertible and the outfit she wore for her investiture at Buckingham Palace earlier this year.
The cream and black outfit was designed by Dame Joan herself and is expected to fetch between $5,000 (£3,300) and $6,000 (£3,900).
She will also sell dozens of dresses and pairs of shoes, as well as her collection of turbans, which are listed for 300 dollars (£200) to 500 dollars (£330). In addition, her Louis Vuitton luggage and a monogrammed Gucci wardrobe bag, bearing the initials J.C.K., will also go under the hammer.
Dynasty fans who fondly remember her as Alexis Carrington Colby will have the chance to snap up some of her outrageous costumes from the cult show, including a fur and leather cape, which is expected to sell for more than 1,000 dollars (£650), and a pair of Yves Saint Laurent earrings, which are expected to fetch more than 2,000 dollars (£1314).
The two love letters from Beatty are dated 1960, when the couple were engaged and he was doing national service. The letters, which are part handwritten and part typed, are in their original envelopes and addressed to Miss Joan Collins at addresses in Rome. In one he addresses her as “bird” and lists his return address as Beverly Hills, California.
The letters, which are accompanied by a playbill from Beatty’s first play and a photograph of the couple, are expected to fetch between 1,500 dollars (£980) and 3,000 dollars (£1,970).
A 14-carat gold perfume bottle given to Dame Joan by West Side Story actress Natalie Wood and her husband Robert Wagner is also up for sale and expected to fetch between 3,000 dollars (£1,970) and 5,000 dollars (£3,300).The engraved bottle, dated 1961, is also accompanied by a typed note from Wood from a decade later.
Fans who want a piece of Dame Joan’s collection will have a chance to snap up more affordable items, such as a gentlemen’s watch and match case, listed for 100 dollars (£65) to 200 dollars (£130), or a set of playing-card ashtrays and other ceramic items, which was expected to sell for around 200 dollars.
The collection will be sold at auction on December 16 and bids will be taken in person, on the phone and online.