Bill Brooks

This was a radical change, welcomed with little enthusiasm by the Christie's board, which wanted to continue its established practice of selling items of major value and importance and passing on others to the smaller house, Phillips. But sharing none of these assumptions about what constituted a suitable market, Brooks started advertising widely and opening departments to sell dolls, Dinky toys and other unremarked items.

He was a keen promoter of "auction probes" in country towns, where the public were invited to bring treasures that had been lying half-forgotten in attics for free valuations by the company's specialist team. A television programme made about one such foray, in Norwich, gave rise to the BBC's Antiques Road Show.

Soon customers were demanding that even their expensive heirlooms be sold in South Kensington, and Brooks scored a significant victory by resisting, for five years, the demand from above to introduce a buyers' premium.

His success also owed much to his reputation as one of the auction world's "great characters". Gavel in hand, he offered a genial patter, and made friends with everyone from porters to directors. Capable of slipping in a "Bless you" when a bidder sneezed, he could also be scathing when confronted with cheek.

Once, he ended up wrestling with a man. Another time, when a dealer offered £420 for a carpet which Brooks thought was worth £450, Brooks told him: "Obviously you do not want this lot, but do come to one of my evening parties. I give them every Saturday, and you can learn how to be generous."

His self-confidence contributed to the increase in turnover, which rose from £1 million to £26 million in 10 years.

A soldier's son, William Frederick Brooks was said to be the heaviest baby recorded in Marylebone when he was born on January 29 1924, weighing more than 13lb. He went to Capland Street School, and left at 14 to become a silversmith's apprentice. He took maths lessons which he paid for by working as a night telephonist.

Determined to learn to fly, at 17 he joined the Air Training Corps, whose commandant praised him for his bravery during five hours' fighting a garage blaze during the Blitz. He went on to train as an RAF pilot in Canada.

When he returned to Britain in late 1944, there was a surplus of pilots; so Brooks volunteered to fly on operations as a flight engineer and second pilot.

In March 1945 he joined No 166 Squadron flying Lancasters, and completed nine operations by V-E Day. These included the sinking of the pocket battleship Admiral Scheer at Kiel; the attack that devastated the island fortress of Heligoland; and the RAF's raid on Potsdam on the night of April 14.

Brooks's final wartime operational sortie was to drop food parcels to the starving Dutch population in The Hague. During the last days of the conflict, he was part of Operation Exodus, flying PoWs back from Germany.

When war ended Brooks was a pilot with No 38 Squadron, flying Lancaster maritime reconnaissance aircraft from Palestine and Malta. He also made numerous long-range patrols over the Mediterranean in support of Royal Navy operations to suppress illegal Jewish immigration to Palestine.

On May 11 1947 he was the captain of one of four Lancasters which took 70 suspected Jewish terrorists from Palestine to Nairobi. He was told by his station commander that all log book entries should record "trooping" as the purpose of the trip; his secret orders stated: "Destroy after reading".

On being demobilised as a warrant officer in 1947 – with the suggestion that he become a hot water engineer – Brooks found a job as a floor sweeper and general assistant at Druce, the Baker Street auctioneers. He progressed to the post of chief cataloguer, and in 1948 married Joan Marshall, who had lost a leg in a motor accident.

A few years later he turned down a job offer from Phillips, instead joining Bonhams in Knightsbridge, at a lower salary but with better opportunities.

He began to concentrate on furniture, and started a new department which dealt with antique arms and armour, and another specialising in furs. In 1964 he became managing director of what later became Debenham Coe in Covent Garden.

When the owners decided to sell the business in the mid-1970s, Brooks recognised that it was well-positioned at the popular end of the market to make an ideal partner for one of the leading firms. Sotheby's rejected a proposal, so he turned to Christie's, arriving in a dark coat and Homburg to be introduced coolly as: "Mr Brooks, who will be working with us."

He was soon creating a convivial atmosphere. His lunch parties for six or eight guests would start at around noon and sometimes continue till 6pm – though there was a problem on one occasion when the porters rushed in to take away the table, as Lot 23; the meal continued as a buffet.

In 1962 Brooks became a Tory local councillor in Paddington. He helped to supervise the merger of Paddington and Marylebone with Westminster into the new borough council. But eventually the Heath government's unpopularity cost him his council seat, and in the 1970s he declined the chance to stand for parliament.

When he retired as chairman of Christie's South Kensington in 1986, Brooks bought a rundown shooting estate in Herefordshire, which he developed with the same gusto he had shown as an auctioneer. "The only difference is, I start each year with 5,000 staff," he would say, "and then shoot the lot of them."

Finally, he and his wife moved to Surrey to be closer to their daughter, Jane St Aubyn, whose husband Nick had regained Brooks's Paddington council seat before going on to become an MP.

Bill Brooks, who died on December 9, is survived by his wife, daughter and two sons, of whom the youngest, Robert, is chairman of Bonhams.