A total of 85% of trains have run on time over the past year

The company said it had made big improvements over the past year with 85% of trains running on time - its best result for six years.

It plans to spend a total of �1.5bn operating, maintaining and renewing the railway in Scotland.

Chief executive John Armitt said the past decade had seen a 42% rise in passenger numbers.

He also said freight had grown by almost 60% over the same period, while there had been a 30% reduction in delays.

Our plans are for a better-performing and more efficient rail network, meeting the aspirations of all our customers David Simpson Network Rail

The company hopes to have 90% of trains running on time by 2009.

The funding is available because the company has beaten its own targets.

Mr Armitt said: "Network Rail's strong performance, focus on value for money and status as a company limited by guarantee has allowed us to free up new money to spend on growing the railway.

"This will be spent on the passengers' priorities and meeting the needs of our freight customers.

"In the last three years we have focussed on getting all the basics right: creating the right structure; improving performance; controlling and reducing costs; developing our people; and being safe in everything we do."

Scotland route director David Simpson said: "Our plans are for a better-performing and more efficient rail network, meeting the aspirations of all our customers."