Catch most MBA graduates off-guard and they'll admit, perhaps bluntly, that chief among their reasons for getting the qualification was to increase their earning power. And most business schools, too, will happily point applicants to statistics illustrating just how much past graduates have increased their income by acquiring those three letters after their name.

You might not think, then, that many MBA programmes would waste much time studying the working practices of public sector or charitable bodies, given the absence of profit in those organisations' DNA.

But you'd be wrong. There are several ways in which many schools ensure that MBA students are exposed to public and charity sector thinking and practice, sometimes labelling the area of study "social enterprise", to make the point that qualities of enterprise are not the exclusive requirement of the commercial world.

This development has become more common as the dividing line between the private and public sectors has blurred. During the last decade, publicly funded bodies have adopted more market-based approaches to carrying out their core functions, and private businesses have become part of consortia providing services in areas such as transport, health and education.

"Whatever organisational environment you come from, you increasingly have to deal with the public sector," says Jeanette Purcell, Chief Executive of the Association of MBAs (AMBA). "And understanding the sector's culture will always be of benefit."

Exact methods of including this dimension in MBA programmes vary, but a frequent approach is to offer electives with a strong public sector flavour. These serve to augment the core content of management skills, found at the heart of every MBA worth its salt, and certainly all those accredited by AMBA.

Glasgow University's School of Business and Management, for example, includes several electives that, either wholly or partly, focus on the public sector. Among topics covered are entrepreneurial behaviour in the public sector, public organisation and management, and partnership working and joined up government.

The entire stream of electives has been approved by the Cabinet Office in Whitehall, and the Glasgow MBA is recommended on a number of government career development websites as one that includes opportunities to specialise on public sector issues. Up to 20 per cent of the cohorts on Glasgow's full and part-time MBAs come from public sector employers in Scotland, including the MoD.

However the electives do not appeal only to students with a public sector background.

"You get a number of the other students opting for some of these courses," explains the head of the school, Angus Laing, "because their businesses frequently engage with the public sector."

Tanaka Business School, part of Imperial College, in London, ensures that all its MBA cohorts (one full-time and two part-time) contain a proportion of students from the public sector.

The result is a constant cross fertilisation of ideas and experience, which proves mutually beneficial to all students, according to Tanaka's Principal, David Begg. "The mix of public and private sector students increases diversity," he explains. "They pick each other's brains."

This cross-sector collaboration at Tanaka has recently borne fruit by the successful completion of an engineering project by a team including an NHS manager and private sector students, all on the full-time MBA."

For some students, though, a flavour of the public sector, either in certain modules, or in the cohort mix, is not enough. And to cater for these, there's a handful of MBA programmes devoted entirely to the area.

Warwick Business School's Master of Public Administration (MPA) has, since 2000, been attracting cohorts of all ages, including desk-bound civil servants and people in front-line situations, such as hospital operating theatres. The mix proves very fertile in the classroom, according to academics.

But the University of Birmingham's School of Public Policy was the first on the map, with its Public Service MBA, which began life in 1990. The school's breadth of faculty enables students to tailor their qualification to numerous different themes, built around the core areas of health, housing, local government and criminal justice.

Professor John Raine, Director of the Graduate School, stresses that the management content at the heart of every student's course is no different to every other MBA. But he suggests there's a danger in assuming that, these days, there's no difference at all between managing in the private and public sectors.

"Public sector managers need to know about private sector business methods. But then they have to use them on their own terms. They are not trying to make money after all," he says.