Girls at single-sex schools do make slightly more progress in maths between the ages of 14 and 16 than those at mixed schools, the researchers found.
Boys, surprisingly, appeared to make slightly less progress in maths in single-sex than in mixed establishments. But the sample of boys' schools in the study (nine) may have been too small to draw firm conclusions.
Using data from 275 UK schools collected in 2001 by Durham University's curriculum, evaluation and management centre, the researchers conclude there is little evidence to favour a return to single-sex schooling.
* Physics undergraduates are arriving at university having never studied mechanics at school.
Mike Savage, professor of fluid dynamics at Leeds University, told a London maths conference he was astonished to discover last year that only eight of his department's 70 students had studied mechanics.
The subject covers many of the mathematical principles behind physics, and Professor Savage said that the university would be laying on catch-up classes next year. A-level maths students must study three modules in applied maths, but Professor Savage said that more now favoured statistics and decision-making, which were easier.
"Public provision of single-sex schools: a questionable route to school improvement", by Peter Daly, of Queen's University, Belfast, and Neil Defty, of Durham University, was presented at a recent conference of the American Educational Research Association