BROOKE Astor was the immaculately dressed grande dame of New York, a philanthropist, taste-setter and host extraordinaire, at ease with royalty and world leaders.

She adored animals, especially dogs, flowers and books. Floral patterns and animal sculptures were decorative motifs throughout her two sumptuous homes: a 14-room duplex on Park Avenue and her country estate, Holly Hill, overlooking the Hudson River in Briarcliff Manor, New York.

Sotheby's is offering the contents of both homes, 901 objects in all, including European and Asian furnishings, Old Masters, Qing Dynasty paintings, tea sets, silverware, jewellery, a porcelain menagerie, more than 100 dog paintings - and even the uniforms of her domestic staff - at a two-day auction that began last night.

Astor died in 2007 at the age of 105.

In keeping with her wishes and life's motto that ''money is like manure: it should be spread around'', all the proceeds from the sale will go to the institutions and causes she supported. They include what she called New York's crown jewels - the New York Public Library, the Metropolitan Museum of Art, the Bronx Zoo, Central Park, plus the Animal Medical Centre of New York, the city's public schools and charities in Maine.

The collection is expected to fetch a total of $US6 million ($A5.8 million) to $US9 million.

The auction comes after a nasty family feud involving her only son, Anthony Marshall. The five-year dispute ended in March with a settlement that freed $US100 million for her charities, and more than halved the amount going to her son, who was convicted of taking advantage of his mother's dementia, partly by engineering changes to her will. He has appealed.

Among the items expected to bring one of the highest bids is an Imperial Chinese gilt-bronze lion clock estimated at $US180,000 to $US220,000.

But not everything in the sale is for deep-pocketed buyers. A group of four white earthenware hounds and a figure of a reclining leopard, for example, carry a pre-sale estimate of $US2000 to $US3000.

''This is a woman who surrounded herself with the things that she loved,'' said Elaine Whitmire, vice-chairman of Sotheby's single-owner collections. ''You can see it in the upholstery, you can see it in the porcelain that she used, floral, animal and Asian-inspired.''

There are 64 pieces of jewellery, including a magnificent emerald-and-diamond necklace and earrings for which Vincent Astor selected the stones in 1958. Mr Astor died before they were completed. Nearly two years later, his wife received the finished necklace from the Italian jeweller Bulgari. Sotheby's estimates the necklace will bring up to $US350,000. The earrings may fetch an extra $US30,000 to $US40,000.

Astor is pictured in the auction catalogue wearing the pieces while chatting with US president Lyndon Johnson at a dinner-dance in his honour at the Plaza Hotel in 1969.

''A woman who dined with kings and queens and presidents - that is a provenance that doesn't get much better,'' Ms Whitmire said.

AP