Universities are facing a staff recruitment crisis, according to two separate reports published on Friday.

Research suggests low pay and job insecurity are discouraging young people from becoming academics.

Universities are also struggling to find senior academics in a wide range of subjects because staff are taking up lucrative offers from the private sector.

'Ticking time bomb'

A survey from the Association of University Teachers says a third of lecturers are over the age of 50, and only one in five is under 35.

It says that compared with the early 1980s, many university departments now have a much larger proportion of staff approaching retirement.

Lecturers' starting salaries can be as low as about �10,000 for "new" universities which have been established from 1992 onwards, or about �17,000 for "old" universities.

The AUT, which has quoted the average lecturer's salary as about �27,000, describes this age profile as a "ticking bomb" which will leave universities short of qualified staff.

In certain subjects the survey found a particularly high number of older staff - with university education departments having over 40% of academic staff over 50 years old - four times as many as the under-35s.

Earning potential

There are also high proportions of staff approaching retirement in biology, maths, engineering and languages.

However, there are much younger staff in medicine and dentistry, where only one in five academic staff are over-50 years old.

AUT General Secretary David Triesman said: "While experience is valuable, too few of our best young people are attracted to academic careers. And they are right. It is now a poor career.

"The universities, as a result, are in a precarious state."

A separate report commissioned by the Committee of Vice-Chancellors and Principals (CVCP) and higher education funding councils says universities are unable to recruit or retain professors and senior academic staff for some subjects because they are being drawn away by the greater earning potential outside of universities.

Subjects affected are identified as engineering, information technology, health and nursing studies, law, business, maths and chemistry.

"Pay is consistently identified as the key factor," says the report, called Recruitment and Retention in Employment in UK Higher Education.

There are also fewer students staying on for postgraduate research in these shortage subjects, suggesting continuing problems in the future.

The lack of senior staff could have a serious impact on advanced research, says the report, with a long-term threat to the "knowledge economy".

Such shortages of academics "are having a significant impact on institutions' ability to develop and innovate in teaching and research. Urgent action is needed to address these issues," said the CVCP's chief executive, Baroness Warwick.

"The UK needs a highly skilled workforce to compete globally, and our students require the brightest and best lecturers in teaching and research."

The CVCP says staff shortages have caused university departments to delay research projects and to depend on part-time and visiting lecturers.

It has called on the government to provide extra investment to allow universities to compete for the best staff.