The MBA used to be very clearly understood. Put that combination of letters after your name and employers knew they were looking at an all-rounder capable of making strategic decisions and leading from the top.

Today things are a little different. The MBA as employers know and love it still exists but so too do a wide range of so-called "specialist MBAs". These new variant can be split into two groups: those that promise to deliver additional expertise in a specific function, be it finance or HR, and those that focus on one particular industry, such as aerospace or the public sector.

Purists are alarmed. Academics contacted for this piece at business schools across Europe and North America variously described a specialist MBA as "a tautology", "a contradiction" and "completely misguided". They argue that an MBA should provide a general business education so that graduates can take on senior management roles regardless of function or industry.

It is the function-specific programmes that most agitate the MBA purists. "It's completely back to front," says Sean Rickard, director of MBA recruitment at Cranfield School of Management. "The people on our programme are already marketing or financial experts and we are helping them out of their silos and into senior general management roles."

Rickard is not alone in believing these new programmes are driven by a need to get bums on seats.

"The rise of specialist MBAs is a response to competitive pressures in an overcrowded market," says Nick Barniville of UCD Michael Smurfit School of Business in Dublin. "Adding an MBA label to what is really a masters programme means it can command a premium."

It's telling that first-tier business schools, the Harvards and INSEADS of this world, are not dallying with specialist offerings. The leading accreditation agencies are also advocates of the MBA as a general management masters degree.

"These specialist degrees are often a marketing gimmick," says Jeanette Purcell, chief executive of The Association of MBAs. "The MBA needs to retain its purpose and definition as a general business education."

Stephan Bourcieu, MBA director Audencia Nantes School of Management, which offers an MBA that focuses on business development, admits the programme is in part a marketing approach. But he stresses there is real demand from employers for managers who can develop new markets. About 60 per cent of the Audencia programme follows the core MBA model with the remaining time dedicated to business development modules, such as marketing new products, venture capital and risk management.

So why not call it a Masters in Business Development rather than dressing it up as an MBA? "We cover everything an MBA does and whereas a Masters is a pre-experience qualification, the average of our students is 31 or 32," says Bourcieu. "It's very different."

Less controversial are those MBAs that specialise in a particular industry. These programmes, which still provide a very general management education albeit skewed to the needs of a particular industry, are proving popular.

ESSEC in Paris, for example, created its MBA in International Luxury Brand Management over 10 years ago. This small programme, which covers luxury goods, from cosmetics to cars, is being expanded to 50 places.

New varieties are springing up all the time. Manchester Business School recently launched an MBA for Construction Executives, with about one-third of the course covering construction specific modules such as collaborative working.

This autumn Cass in London will launch the world's first Executive MBA in Film, which will combine the fundamentals of an MBA with options in film finance and distribution. David Sims, an associate dean at Cass, believes the new programme will meet the needs of those seeking to fast-track a career in the film business.

Yet there is an argument that good managers can manage any business. An MBA should be a launch pad to senior management roles in which individuals must understand how an organisation works, take a strategic view of a problem and make big picture leadership decisions. These high flyers employ lower ranking managers with specific functional or industry expertise to fill in any technical gaps (and who may in time sign up for an MBA themselves).

As Sean Rickard at Cranfield points out, at a certain level of seniority it really doesn't matter whether you're running a football club, a charity or an airline. "The top business people in the world seem quite able to move from industry to industry with no trouble at all," he says. And it is those positions the MBA graduates of the future should be filling.

'This MBA would benefit a lot of people in construction'

Property developer Kevin Gunputh (pictured centre left), 27, is studying for an MBA for construction executives at Manchester Business School.

My company was originally set up to acquire and operate care homes but increasingly my career is moving down the construction path. I've moved into finding plots of land and building new care homes, which means a better end product that meets all the latest regulations. But I have no real experience of construction other than what I've been learning on the job. It means I have to rely very heavily on other people for their input.

Before I found out about this MBA, I had thought about doing a Masters or some kind of NVQ to learn about the ground mechanics of construction. The MBA for construction executives is better because it will give me the project management skills, which is what I need in this role. My bank manager is also very pleased I'm doing this. These are £5m or £6m projects and the MBA gives him some reassurance.

I'm in the first semester and we're covering the core content of an MBA. We have just done a module on supply chain management, which was really fantastic. I am already thinking about my own organisation and how to put what I've learned into practice. I think this is a qualification that would benefit a lot of people in the construction industry. It's an industry with a lot of talented people but they don't always have the all-round skills and knowledge to sustain their success during economic downturns.