Roy M. Huffington was a struggling Texan wildcatter who struck it rich in the oil and gas reserves of Indonesia. He went on to become US Ambassador to Austria under President George H. W. Bush.

Bush, himself a former Texan oilman, was a long-time friend of Huffington who had been a significant sponsor of his political campaigns, and he succeeded where President Ronald Reagan had failed in persuading Huffington to become Ambassador to Austria in 1990 after he had sold his company for an estimated $600 million, according to Huffington.

He said that his love of the oil business had been too great up until that point: “It’s a fascinating business. Reagan was after me for ambassadorship three times but I was still building my company so I wasn’t interested.”

After stepping down from his ambassadorial role in 1993 Huffington turned his attentions to philanthropy, donating large sums to charities and institutions in Houston.

He was the former father-in-law of Arianna (Stassinopoulos) Huffington, the Republican turned liberal activist who unsuccessfully ran for the California governorship and set up an online newspaper, the Huffington Post, described as the liberal answer to the Drudge Report. She was married to his son, Michael, who was briefly a congressman and spent $30 million on a campaign to become a senator, which he narrowly lost. They divorced in 1997.

The oil tycoon was born Roy Michel (later changed to Michael) Huffington in 1917 near Tomball, Texas. His father, who worked in the oil industry, was killed in an accident in Venezuala when he was just 14. His mother struggled financially, and Huffington took on newspaper rounds while attending North Dallas High School to help to support the family. After school he took a degree in geology in 1938 at the Southern Methodist University and then secured a teaching fellowship at Harvard where he obtained a masters and then a PhD in geology.

He served in the US Navy from 1942 to 1945 on the aircraft carrier USS Hornet and received the Bronze Star with Combat V and the Presidential Unit Citation for his participation with Task Force 58 in the Pacific. After leaving the Navy he decided not return to teaching — which he had enjoyed at Harvard — because the pay was too poor, and took a position as a field geologist for Humble Oil and Refining Company (now Exxon).

In 1945 he married Phyllis Gough. They lived in Midland, Texas, and New Mexico before moving to Houston in 1951. His son, Michael, recalled in an interview that his father moved his young family from one shabby apartment to another as he prospected for oil across New Mexico and Texas.

On settling in Houston, Huffington poured what little money he could raise into punching wells, but without hitting the jackpot. In the late 1960s his company, Roy Michael Huffington, known as Huffco, which was set up in 1956, started exploring in Indonesia. As a geologist he was attracted to Indonesia because its coastal delta formations were of the same age as those in the Texas-Louisiana Gulf Coast area.

He made a vast gas strike there in 1972 which earned him millions of dollars over two decades in partnership with the Indonesian Government. The business was sold to Chinese Petroleum in 1989. Forbes estimated his net worth to be more than $300 million.

Huffington had already become a fan of Austria’s conservative, business-orientated political culture before succeeding Henry Grunwald as US ambassador to the country. He had also taken a great interest in Eastern Europe following his travels to the region and wished to teach the Eastern bloc about entrepreneurship and free markets.

He and Phyllis set up the Huffington Centre on Ageing at the Baylor College of Medicine in 1988 which became a leading centre in geriatric research and health care for elderly people. The Huffington Foundation, which he established in 1987, gave $10 million to the Southern Methodist University to provide financial support for staff and students.

At one stage he was donating money to 350 groups a year, arguing that you cannot take money with you. In recent years the number of groups receiving donations had dwindled to around 200. Huffington was on the board of trustees of Baylor College for 20 years. He also served as chairman of the US-based Asia Society for much of the 1980s.

He was a workaholic whose weekly schedule involved working for 80 hours on five hours’ sleep a night. He would occasionally take a day off to go shooting. Last year, when asked what was next on his agenda, he replied: “I don’t know but I hope it will be Heaven. I don’t think I will ever retire.”

Commenting on his death, George Bush senior said: “Not only was he one of this country’s great entrepreneurs, he was also a pioneer in the oil business and gave selflessly of his time and energy as the US Ambassador to Austria.”

Huffington is survived by his son, Michael, and his daughter, Terry.

Roy Huffington, oil magnate, US Ambassador to Austria 1990-93, was born on October 4, 1917. He died on July 11, 2008, aged 90