ALMOST a third of Scottish university research is now ranked amongst the best in the world after a significant improvement in quality, new figures show.

A UK-wide exercise to assess the quality of higher education research has seen 29.3 per cent of submissions from Scotland classed as "world-leading".

In 2008 - the last time the rankings were compiled - just 15 per cent of Scottish research was rated so highly.

The 2014 Research Excellence Framework (REF) has also classed 47.6 per cent of research at universities here as "internationally excellent" compared to just 37 per cent six years ago.

Scottish universities also featured prominently in a league table of UK institutions drawn up on the basis of the REF results.

The table, compiled by industry publication Research Fortnight, ranked Edinburgh University top in Scotland and 4th in the UK followed by Glasgow, St Andrews and Strathclyde.

As well as topping the rankings in Scotland, Edinburgh University research in sociology, earth systems and computer science was rated the best in the UK.

Edinburgh also came first in the UK for agriculture, veterinary and food science, under a joint submission with Scotland's Rural College, and in general engineering, with a combined submission alongside Heriot-Watt University, in Edinburgh.

At Glasgow University, human geography was rated best in the UK for "internationally excellent" or better research, while urban studies came joint first.

Dundee University came top in the UK for biological sciences and Strathclyde University's department of physics came first in the UK ahead of Oxford and Cambridge. Aberdeen University was rated top in the UK for the work of its environmental and soil scientists.

The huge improvement in Scottish research quality, which mirrors an increase at institutions across the UK, was welcomed by ministers, academics, institutions and the Scottish Funding Council (SFC), which distributes public money to universities.

Officials said the progress reflected greater investment, more targeted funding towards the best work and the practice of bringing together academics from different institutions to collaborate together in research pools.

Angela Constance, the Education Secretary, said the REF results showed all Scottish institutions were producing world-class research.

She said: "Our universities have a strong track record of attracting funding from around the world and the Scottish Government will continue to support them to develop new ways of thinking that will further strengthen our economy and improve the lives of people in Scotland and around the world."

Professor Pete Downes, convener of Universities Scotland, which represents university principals, said Scotland's higher education institutions had performed "outstandingly well".

He also welcomed a new REF ranking which assesses the impact university research has on the wider community.

He said: "Scottish universities have been shown to excel in the impact of their research, with over 85 per cent being found to have had either outstanding or very considerable impact, a performance which is significantly better than the average across the UK."

Laurence Howells, chief executive of the Scottish Funding Council, said it was "particularly satisfying" that Scotland's pioneering approach to collaboration through research pooling has helped to underpin the success.

However, Mary Senior, Scotland official for the UCU lecturers' union, called for greater job security for all staff, including those with research ranked at lower levels.

The results of the REF are hugely significant to academics because they determine how much research funding they are granted and a poor performance can even lead to the closure of a department.

Ms Senior said: "Too often our world-leading research is being conducted by people with little or no job security. Universities must avoid any knee-jerk reactions to the results or use perceived low scores in other areas to try and make unnecessary cuts."

The REF is carried out every six years and provides an assessment of the quality of universities' research in all disciplines.

This year's results were based on analysis of research of 52,061 academic staff from 154 UK universities which was peer-reviewed by a series of panels comprising UK and international academics and industry specialists