LONDON -- Britain said yesterday it would pump £33.5-billion ($77.5-billion) into rebuilding its railway system, which has been blighted by crashes, delays and strikes and posed a growing embarrassment to the government, according to a wire service report.

But the Strategic Rail Authority's 10-year plan, aimed at reversing years of underfunding, conceded that the private sector would take some convincing to match public investment in the network, called the worst in Europe by one minister.

The SRA estimates that up to £70-billion is needed to modernize tracks and trains, ease overcrowding and cope with an expected surge in passenger numbers and freight volumes.

The public spending announced yesterday is a 15% rise on a provisional figure given last year and the SRA said it would not hesitate to ask the government for more.

"What this plan says is 'enough is enough,' " said Richard Bowker, SRA chairman. "This is going to mark the line in the sand for our railways. But more importantly ... this plan is supported by the government, and now we are going to deliver it."

Broken up and sold off in the mid-1990s, Britain's railways have lurched from one crisis to another in recent years.

A series of crashes hurt passengers' confidence, emergency track repairs led to massive delays and then the network operator Railtrack was forced into administration last October. This year has begun with strikes and calls for the scalp of Stephen Byers, the Transport Minister.

Much of the investment is focused on London and southeast England, where millions of people rely on trains to get to work. The aim is to bring short-term improvements to the network while building toward government targets of 50% growth in passengers and 80% growth in freight.

Mr. Bowker said the extra government cash would come from the existing spending budget. No new money was being made available. But opposition politicians and financiers said private investors would be reluctant to put still more money into the rail network, particularly after Railtrack's collapse.

Railtrack shareholders want to sue the government to recover their cash.

"There is no doubt that the risk premium for dealing with the U.K. government has increased," said Simon Haslam, chairman of the Railtrack Shareholders Action Group, which includes some of the world's biggest investment funds.

Railtrack Group PLC, owner of the operating firm in administration, hailed the strategic plan, but questioned whether its financial foundations were solid enough.

"The plan assumes a massive contribution from the private sector," chief executive Steve Marshall said.

"Currently, the spectre of the treatment of Railtrack -- as it languishes in administration -- and its investors who are being invited to underpin massive new investment casts a shadow over the delivery of the plan."

He called on the government to restore investor confidence by making sure Railtrack shareholders got fair value for their investment. Measures in the plan include the addition of waiting rooms and toilets at all stations -- criticized by some rail users as cosmetic improvements. The paper confirms money will be spent on safety, replacing old-fashioned slam-door trains and the completion of the first phase of the Channel Tunnel fast rail link between London and the Anglo-French tunnel at Folkestone.

Key railways, including the west and east coast mainlines running from London to Scotland will also be upgraded.

Passenger group Transport 2000 gave a cautious welcome to the news, saying the government was finally "biting the bullet." Richard Branson, the chairman of Virgin Rail, said ministers had recognized public anger and made transport a top priority. "The government have been given a nasty fright," he said.