The government auditors, in their Major Projects Report 2004, found "little evidence" of any improvement in the way the Ministry of Defence (MoD) has handled the multi-billion-pound projects despite passing efficiency-minded reforms.

Delays on the equipment programs also increased an average of three extra months, during the year-long period through March 2004, the report said.

The 20 procurement projects will now cost a total of 50 billion pounds, six billion -- or 14 percent -- more than initial estimates, it said.

The budget watchdog's figures show that even with projects run under a "smart acquisition" reform system meant to make them more efficient, the MoD ran up excess costs and delays.

One of those projects, to build the Type 45 destroyer, was delayed by an extra 18 months, due to what the NAO said was a "lack of realism" in creating its original planning timeline.

Nimrod Mk4 surveillance planes cost 408 million pounds more than planned this year. Originally due to enter service in early 2003, they are now expected to be deployed in the second half of 2009.

The Joint Strike Fighter, developed together with the United States, overran costs by 372 million pounds this year because US contractor Lockheed Martin had to redesign them after the original was too heavy to operate on future Royal Navy aircraft carriers.

Comptroller and Auditor General Sir John Bourn, the head of the NAO, expressed "particular concern" that problems were being encountered in the more recent projects.

"There must be greater certainty as to when equipment will be ready for service and there must be greater control of costs. If not, some capabilities may have to be foregone or delayed to compensate for rising costs," he said.

Defense spokesman for the opposition Conservatives Gerald Howarth called the report a "damning one" for the defense ministry's handling of its procurement projects.

The findings follow a highly critical report earlier this year by a parliamentary defense committe which deplored "woeful" performance by the MoD's Defence Procurement Agency (DPA) and said it had "let down" the British military.

While the NAO said the 2003 results were better than the preceding year, which overran costs by 3.1 billion pounds, it also foretold greater budget woes. "We expect there to be problems emerging on existing projects in the future," it said.