IF someone told you that your company could save millions of pounds from its advertising and marketing budget without losing any sales, you'd be delighted . . . wouldn't you?

Yet for some reason the tobacco industry, which for years has assured us that advertising and sponsorship don't increase cigarette sales, has been less than enthusiastic about the European Union's decision to ban these activities.

The purpose of advertising, they have always maintained, is brand rivalry, rather than an attempt to lure young new smokers to the habit. Surely the worst that can happen is a stabilisation of the market. No posters to tempt the Embassy puffer to switch to Silk Cut. No Formula One car racing past to inspire the Benson and Hedge's gasper to move to Marlboro.

''The ban will not reduce tobacco consumption nor stop children smoking,'' was the reaction from the Tobacco Manufacturers' Association. So why all the fuss?

I tried to ask some of the cigarette companies yesterday, but their spokesmen weren't too easy to get hold of. Perhaps they were all sitting in darkened rooms, screaming. The fact is that a product which kills thousands of its customers every year has to market itself pretty hard to keep up the numbers, so let's get real - the EU ban is a major blow to the industry.

What have they got up their sleeves once the posters, the newspaper and magazine ads, and the sponsored sports, fashion shows, and concerts are all gone? The most open ploy will probably be a price war, but with 80% of the price accounted for by tax, there is limited room for manoeuvre. Perhaps gift coupons will return to vogue.

But the real effort is likely to take place behind the scenes, in - dare I say - smoke-filled rooms, as the tobacco giants consider some wheezes that they'd rather you didn't know about.

Like genetically-engineered tobacco, for example. This ploy, and the web of deceit that surrounded it, has been exposed in a series of court actions by various US courts against the tobacco industry.

According to the indictments that have been piling up from coast to coast, Brown and Williamson, a US subsidiary of British American Tobacco, spent 10 years in cahoots with a company called DNA Plant Technology Corporation secretly developing the plant on a farm in North Carolina, with the aim of creating a nicotine content twice the level found in normal flue-cured tobacco.

The enhanced addictiveness of cigarettes made from this tobacco would obviously give its makers a crucial edge in maintaining its market share in Europe and US, and - perhaps more importantly to the industry - help it to penetrate the less-developed markets of Eastern Europe and the Third World, where the kind of restraints being imposed in the EU do not apply.

According to the indictments, Food and Drug Agency investigators discovered the existence of Y-1, as the novel plant was called, in June 1992, a month after Brown and Williamson had flatly denied being engaged in any breeding of tobacco for high or low nicotine levels.

Brown and Williamson had taken out a Brazilian patent for the new plant, which was printed in Portuguese. Using the North Carolina seeds, Brown and Williamson and a Brazilian sister company, Souza Cruz Overseas, grew Y-1 in Brazil - in contravention of Federal laws banning the export from the US of genetically-altered material - and shipped it to the United States where it was used in five Brown & Williamson cigarette brands including three labelled ''light''.

As part of its cover-up, Brown & Williamson instructed DNA Plant Technology to tell the FDA investigators that Y-1 had never been commercialised.

Only after the FDA discovered two United States Customs Service invoices indicating that more than a million pounds of Y-1 tobacco had been shipped to Brown & Williamson did the company admit that it had developed the high-nicotine tobacco.

When the company's deception was uncovered, company officials admitted that close to four million pounds of Y-1 were stored in company warehouse in the United States.

This week's New Scientist throws light on another industry tactic, trying to recruit people of influence - like doctors and scientists with impressive credentials - to foster or participate in research which takes the heat off tobacco.

This may mean trying to discredit independent research about the effects of smoking - and particularly passive smoking, which makes the habit everyone's business - by

subtly shifting the blame towards deficiencies in building design and ventilation, or by diverting attention to other environmental or lifestyle hazards which cause the same problems as cigarettes.

This tactic has a long tradition, going back to the days when doctors and celebrities were used to extol the health properties of various brands.

During the 1950s in the US the makers of Chesterfields used a radio and TV personality called Arthur Godfrey to assure listeners and viewers that his favourite brand would have no adverse effects on the throat, sinuses, or affected organs. He later died from lung cancer.

When researchers like Bradford Hill and Doll in the UK established the connection between smoking and lung cancer the cigarette companies formed the Tobacco Industry Research Committee, purportedly to research the health issues, in reality to throw a smokescreen round them.

The industry is running out of tricks, but it still turns over billions of pounds, and its products are still the biggest preventable cause of death in the Western world.

With all that money to be made, and all those corpses to replace with new recruits, they won't give up without a fight.