It is perhaps self-evident that the objective of business is to satisfy the needs of customers to find out what they are, to tailor the product to meet them and then to sell it to those customers worldwide.

Achieving these aims is the purpose of marketing yet too many companies are frightened of the discipline, says Sir George Bull, who retired last week as co-chairman of Diageo, the branded food and drink company formed last year by merging Guinness and Grand Metropolitan.

During 42 years in the drinks business mostly with Grand Met he became one of Britain's leading marketeers, promoting global brands such as Smirnoff vodka and J & B Rare Scotch whisky. One of the few people with a marketing background to reach the top of a large group, he wants to convince British companies of the benefits of better marketing.

"So much of what they do is sell what they have to sell irrespective of what people want to buy," he says. "My mission is to persuade them to get their arms around marketing, understand it, see how it can help them and then make use of it.

"We are a fundamentally production-oriented society and have been since we led the world into the industrial revolution. Our smokestack industries drove the economy for 150 years, but it's no longer just a matter of producing widgets here. It's much more a question of adding value to the widgets and then marketing and selling them around the world.

"We could become so much more successful with better marketing, especially in exporting, which is an absolute requirement for the economy."

It is a gospel Sir George hopes to continue preaching as vice-president and honorary fellow of the Chartered Institute of Marketing, honorary fellow of the Marketing Society and president of the Advertising Association. He was a founding director of the Marketing Council, the umbrella body set up to promote marketing in increasing British competitiveness in 1995. In all these roles, he has tried to educate the City about the importance of his discipline.

"It is now irrefutably proven that companies which are good at marketing produce better results over time for their shareholders than those which don't. That is the essence of my message."

Sir George's love affair with marketing began when he left the Coldstream Guards after national service. He did the 1950s equivalent of a graduate entry scheme at Dorland, the advertising agency, which gave him the opportunity to see all sides of the business. "Some boys wanted to become engine drivers," he says. "I had always been interested in advertising in what made people buy."

After a year, he left to become a salesman in the wine and spirit business, spending five years selling Hennessy cognac in south-east Asia. When he returned to Britain, he became UK marketing director of the newly-formed International Distillers & Vintners, the first drinks group to have a full-scale marketing department with brand managers.

The new department demonstrated its capabilities with the launch of Smirnoff vodka, built almost from scratch to become Britain's largest spirits brand. Its advertising campaign launched a memorable series of ads around the theme of "I was just an accountant until I discovered Smirnoff. The effect is shattering."

Later he ran IDV's export division, responsible for promoting the J & B Rare Scotch whisky globally. Today, it is the world's second biggest Scotch brand.

In 1988, Sir George became chairman and chief executive of IDV, which had become part of Grand Metropolitan in 1972. He became chief executive of Grand Met in 1993 and succeeded Sir Allen Sheppard as chairman in March 1996. Last year he surprised the world when he announced the group's merger with Guinness to form Diageo.

"The drinks industry is very fragmented in comparison with other consumer industries," Sir George says. "All the big groups had been sniffing round each other for several years, but it was clear there was one outstanding combination us with Guinness."

He occasionally dined with Tony Greener, Guinness chairman and chief executive, to discuss industry issues. When Sir George hosted a dinner at Duke's Hotel on April 10th, 1997, he decided to pop the question.

"Because the two groups knew each other so well already, we were able to announce the deal one month later without any leak. The preparation showed when we completed the merger inside the eight-month timetable we had set ourselves."

Sir George is surprised that so far there have been no repercussions in the industry the much predicted mergers of rivals have not happened.

"One reason is both of us were the best partners for most of the others in terms of fit between brands, geographic coverage and so on. I believe there will be more consolidation, however, and although we are big and powerful, there is plenty of room for the other very large businesses."

Sir George will continue as a non-executive director of Diageo and has become non-executive chairman of J. Sainsbury, the supermarket chain, following the resignation of Lord David Sainsbury to join the British government. At first sight, moving into grocery retailing seems a strange move for a man who has become the doyen of branding in the consumer goods sector.

"Sainsbury has all the attributes of a brand with its stores, logos, people and own-label products," he says. "I don't see anything different from that which has interested me all my life: the development and promotion of a leading brand."