The BBC's Simon Montague: "The crash was the worst since Clapham nine years before"

Seven people died and more than 150 were injured when an express train collided with an empty freight train which was crossing the main line at Southall, west London on 19 September, 1997.

It is thought to be the first time a privatised railway company has faced a manslaughter charge in the aftermath of a rail crash.

Great Western will also be prosecuted by the Health and Safety Executive.

The decision comes after a lengthy investigation by British Transport Police into automated signal systems on the passenger train.

The passenger train driver, Larry Harrison, has already been charged with manslaughter and is due to make another court appearance on Friday.

Both the manslaughter case against the rail company, which has been brought by the Crown Prosecution Service, and the HSE prosecution are due to be heard at Ealing magistrates court in west London on 12 January.

A public inquiry into the accident began in February this year but was adjourned after just two hours pending the outcome of any prosecutions that might be brought.

News of the announcement was welcomed by Des Collins, the senior partner of Collins solicitors of Watford, Hertfordshire, whose firm represents about 40 people either injured in or bereaved by the Southall crash.

"It is vitally important in cases like this that we look beyond the first cause of a railway accident," he said.

"My clients will be relieved to see that further investigations are being carried out into the circumstances of this accident. To simply blame the driver in these cases is to show an inability to understand the infrastructure of the railway system."