Runners wanting to take part in this year's Great North Run should not give up hope, according to its organisers.

The limit for entries to the world's biggest half-marathon has already been reached in the quickest time ever, three months before the official closing date. But organisers say places are still available by running for charity.

The main charity backing the run, the Leukaemia Research Fund, has reserved 1,000 places for runners while dozens of other organisations also have set aside places.

Cancer Research UK still has room for 350 runners who can guarantee to raise £300 sponsorship.

Despite fears that the race was in danger of becoming a closed shop to new runners - due to a procedure whereby those who take part in a run receive an application form for the next - only a fraction of this year's runners took part last year.

Organiser Nigel Gough said of the 47,000 runners signed up, about 9,000 ran the 2002 half-marathon.

He said: "People travel from far and wide for the run and often just do it once, or get injured. It's not an exact science, a lot of people can't take part again for various reasons."

The BUPA Great North Run will take place on Sunday September 21st and covers a 13 mile route, starting in Newcastle and finishing at South Shields.

To find out which charities still have places, log on to www.greatrun.org or ring the Great North Run's South Tyneside office on 0191-4562251.