Former chairman of the family threadmaking firm; Born July 25, 1924; Died May 1, 2009.

Sir William Coats, who has died aged 84, was the last member of the renowned Coats family to head the historic Paisley threadmaking company that still bears their name.

The family were major benefactors to the Paisley area, donating the museum, the library, the Coats (astronomical) Observatory on Oakshaw Street and the Fountain Gardens on Love Street. They also built the Thomas Coats Memorial (Baptist) Church whose spire dominates the skyline and which was named after Sir William's great grandfather.

Sir William was the great-great-grandson of James Coats, who built a small thread factory behind his house in Ferguslie, Paisley, in 1826, that grew into the world's largest public company at the turn of the twentieth century.

It is now a billion-pound global enterprise, Coats plc, the world's largest supplier of industrial thread, but it is owned by the London-based investment firm Guinness Peat Group, and the Coats family connection is no more. It is also long since gone from Paisley.

Sir William worked all his life for the firm, initially known as J & P Coats but, after a 1960 merger, Coats Patons. He was chairman of Coats Patons from 1981 until his retirement in 1986.

Although one of Sir William's surviving sons, Brian, also worked for the firm, he, too, is now retired, leaving the family represented only in the famous name.

William David Coats was born in Glasgow, son of Thomas Heywood Coats of Levernholme, Nitshill, where the young William grew up, and Olivia Pitman. The house is now a nursing home. Following family tradition, he went south for his education, first to the prestigious Lockers Park boarding school, Hertfordshire, and then to Eton.

Immediately on leaving school, he served with the Royal Artillery and the Royal Indian Artillery from 1943-47, latterly as a captain. He fought in the Far East towards the end of the war, an experience which, according to his family, he never talked about.

He married Elizabeth MacAndrew, daughter of the 1st Baron MacAndrew, in 1950.

He joined J & P Coats in January 1948, serving in various positions until he was named a director of Coats Patons after the 1960 merger. He was appointed deputy chairman in 1979 and chairman two years later.

He also served as a director of numerous institutions, including Clydesdale Bank, where he served for many years as deputy chairman, the Caledonian Trust and the Weir Group.

In the year of his retirement, 1986, after another merger, the threadmaking company became known for several years as Coats Viyella before being renamed as the current Coats, now also the world's second largest zip manufacturer and based in Uxbridge, Middlesex.

Although he was occasionally assigned to Coats' factories abroad, notably in Italy and Mexico, Sir William spent most of his career based in Glasgow.

One of his proudest achievements was putting the Coats pension fund on an even keel during difficult times in the 1970s by cutting the company's dividend payments. It was an unpopular move in the City but it proved to be prescient and the current Coats pension fund is considered to be one of the best-funded and most successful in the world.

He was awarded an honorary law degree, LLD, by Strathclyde University in 1977 and knighted in the 1985 New Year's honours list.

Sir William retired to his home in Symington, Ayrshire, where he tended his cherished lawn, his dahlias and azaleas.

He also shot pheasant, grouse and duck, and played at Prestwick Golf Club, where, at 6ft 3ins, he towered over the tee and served for a time as club captain.

He also dedicated much of his time towards cancer research and was a former chairman of the Glasgow appeals committee of the Cancer Research Campaign. According to his family, punitive death duties meant he received only a fraction of his inheritance from his wealthy father at the peak of the company's success.

Sir William's grandfather's brother, George Coats, was the first Lord Glentanar, who in the early twentieth century owned the Glen Tanar estate near Aboyne, Aberdeenshire, now a popular holiday destination. Today it is owned by Michael Bruce of the Bruce family of Balmanno Castle, Bridge of Earn, related to the Coats family through marriage.

Sir William Coats died of pneumonia in Malin Court care home, Turnberry, where he had been looked after for almost three years, suffering from Alzheimer's.

He is survived by his wife Elizabeth, sons Adrian and Brian, daughter Frances, and grandchildren Julia, Rachel, Andrew, Alistair, Alexandra and Jonathan. By PHIL DAVISON