According to official statistics, nearly 7% of the 13,900 students who graduated from Scottish universities in 2010/11 are in manual work, compared to 4.5% in 2006/07.
The Higher Education Statistics Agency (Hesa) also found 13% of Scottish graduates are working in sales or customer services, compared to 9.5% five years ago.
The figures mean a total of 2600 graduates are now in sales or manual work, against the 1780 who graduated in 2006/07. Over the same period, the proportion going into management has fallen from 7.5% to 6.2%, while entry into the professions, such as law and medicine, has dropped from 33.5% to 31.2%.
The statistics support growing anecdotal evidence that former students are finding it harder to secure graduate jobs – although the vast majority still go on to secure employment appropriate to their qualifications.
In the last few months major companies, including oil giants BP and international accountancy firm Ernst & Young, said they would be expanding graduate recruitment in Scotland from this year.
Overall, the Hesa study found 90% of graduates either find work or go into further study, and only 7% are unemployed, compared to 9% across the UK and 10% in England. Scottish unemployment for the rest of the population is running at 8.2%.
But graduate employment in Scotland has suffered in recent years – there was an unemployment rate of just 4% in 2006/07.
Angela Constance, Minister for Youth Employment, highlighted Scotland's stronger performance in relation to the rest of the UK.
But she added: "We recognise that the current economic climate is challenging for graduates to get into the job market.
"This is why, as part of our wider work to tackle youth unemployment, we are committed to ensuring that each and every graduate has the support they need to secure long-term sustainable employment."
Alastair Sim, director of Universities Scotland, which represents university principals, said degrees were still a valuable commodity in the jobs market.
He pointed to recent figures that show the average starting salary for a graduate from Scotland is £21,000, while graduates typically continue to earn 50% more than non-graduates over their working lives.
He said: "The recession has taken the heaviest toll on the jobs market for all young people; graduates have not been totally immune.
"However, despite the tough times, graduates are still in demand from employers."
Robin Parker, president of NUS Scotland, which represents students, defended the worth of a university education, saying: "Having graduates in jobs usually reserved for school and college-leavers can hugely worsen youth unemployment for those with few or no qualifications."
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