Peter Lehmann was a gas industry executive who helped to change British Gas from a state monopoly to a competitive energy company. At the same time, he retained a deep concern for the industry’s social responsibilities, and after retiring from the board of Centrica he became chairman of the Energy Saving Trust and, latterly, the Fuel Poverty Action Group.

Peter Julian Lehmann was born in Littleborough, Lancashire, in October 1944, the son of Jewish refugees from Nazi Germany. He grew up in a left-wing intellectual atmosphere and remained a lifelong supporter of the Labour Party. Colleagues at British Gas believed a photograph existed of Lehmann selling the Socialist Worker outside Tooting Bec Tube station, although Lehmann dismissed this as a myth.

After Manchester Grammar he studied economics at Corpus Christi College, Oxford, and gained a doctorate in industrial economics at the University of Sussex. In 1970 he joined British Gas in the economic planning department. This was the period when the country was being converted to North Sea gas, a process that required substantial investment in pipelines and other infrastructure. British Gas had also to develop sophisticated analytical and negotiating skills to deal with the petrochemical multinational companies that supplied the gas.

In 1976 Lehmann surprised his colleagues by taking a pay cut to run a local engineering unit in South London: it was an early example of his idealism. He returned to the corporate centre in 1980 to lead the team which forecast energy demand and prices. In 1983 he joined the gas-purchasing department, where his toughness and quick intellect came to the fore.

The privatisation of British Gas in 1986 caused him fewer political difficulties than might have been supposed. Though he remained devoted to the ideals of public service that had attracted him to British Gas in the first place, he also recognised the importance of competition in delivering value to the consumer.

British Gas adapted to the loss of its domestic monopoly, in part, by investing in gas industries overseas. As director of the British Gas Global Gas division in the early 1990s, Lehmann oversaw expansions into Germany, Trinidad and Argentina. The German investments were especially significant because historically German firms had dominated the European industry and resented outsiders.

Lehmann led the development of Atlantic LNG, a project to export liquefied natural gas from the island of Trinidad, for British Gas. The local and corporate politics were complicated, and Lehmann was widely credited with playing a brilliant game with an initially weak hand. At the same time as convincing a reluctant British Gas board of the merits of the project, he lobbied tirelessly in Trinidad, where he found the authorities well disposed to a British partner to counter the American investors already present. The Atlantic LNG project is now regarded in the gas industry as having commercially and technically revolutionised this important sector of the worldwide gas industry.

With the British gas market beginning to open to competition, Lehmann moved into a crucial phase of his career. He was instrumental in the acquisition by British Gas of a stake in Natural Gas Clearinghouse (NGC), a big US gas trader, and encouraged the transfer of staff, information technology and trading techniques to Britain. Back in London, Lehmann became the British Gas lead negotiator with the Government and regulator over the future shape of the energy market, and of British Gas itself. The new chairman, Sir Richard Giordano, saw that adaptation of the status quo would not work, for British Gas or for the consumer. Giordano favoured a radically different industry structure and charged Lehmann with fighting the battle in Whitehall.

The essence of the plan was to split the company into three parts. The pipelines, initially known as Transco, now National Grid Gas, were separated from the part that bought and sold gas (today known as Centrica), and from the global gas and exploration divisions which combined in a company called BG.

National Grid Gas would transport gas for the shippers — that is, Centrica and its new competitors — on a non-discriminatory basis. The regulator insisted that in the early years the market be tilted against Centrica. Lehmann accepted that this was necessary to encourage competition, but worked hard to improve conditions for his company. He was also determined that the new rules would offer protection to vulnerable consumers.

In 1998 Lehmann was appointed to the board of the new Centrica as commercial director. He was the only representative of the ancien régime on a board which, under Sir Roy Gardner, had prodigious marketing skills. Gardner valued Lehmann for his understanding of the gas industry, which became more vital as the British market was exposed for the first time to continental competition. Lehmann also directed Centrica’s move into electricity. In other circumstances he might have been Centrica’s chief executive. Lehmann retired from Centrica in 2001 to take up the chairmanship of the Energy Savings Trust (the EST co-ordinates energy savings initiatives). Under Lehmann’s leadership it focused on getting energy companies to help their customers. As one colleague said: “Peter ensured that several hundred thousand more British homes were properly insulated.” He retired from the EST in 2005. He was appointed CBE for services to the gas industry (“and its customers”, as he always insisted).

Gaz de France, itself facing the sort of liberalisation British Gas had undergone a decade earlier, also appointed Lehmann to a non-executive directorship, an extraordinary distinction for an Englishman, even one fluent in French.

Lehmann cared passionately about the environment and fuel poverty, and continued to work tirelessly for both of these causes. Among a number of environmental initiatives to which he lent his expertise, he was chairman of Greenworks, a not-for-profit company that restores and recycles used office furniture, employing many formerly homeless and other disadvantaged people.

With the rise in energy prices in 2004, Lehmann began to devote more time to analysing the true cost of energy, becoming an adviser on fuel poverty to the Department for Work and Pensions. He was aware that the spot price of gas or electricity did not represent the actual cost of these commodities to the sellers, and lobbied effectively on behalf of the Fuel Poverty Action Group for greater transparency, and for enhanced measures to help poor consumers to pay their bills.

Despite his easygoing nature, Lehmann had inflexible standards in business. His concern was to deliver value to his company, to shareholders and above all to consumers, however difficult it might be to reconcile these three imperatives. His lifelong commitment to the Labour Party did not preclude friendships with and respect for those with different beliefs.

Lehmann died after contracting sporadic CJD, a rare and fast-acting form of the degenerative brain disease. He died within weeks of its diagnosis. Lehmann is survived by his wife, Tara, whom he married in 1970, and their two children.

Peter Lehmann, CBE, gas industrialist, was born on October 17, 1944. He died on November 4, 2008, aged 64