A major software company involved in the government's overhaul of its health care IT system has seen its chief executive officer resign less than a week after an accounting restatement caused it to slash profit projections.

In a statement yesterday, departing iSoft CEO Tim Whiston said he was "concerned that my continued role with the company may represent a source of negative speculation and comment, being an unhelpful distraction to those within it".

Whiston will be replaced by John Weston, iSoft's chairman, until a permanent replacement is found, the company said.

iSoft, based in Manchester, makes software applications for the healthcare industry. The company is a subcontractor for Accenture and Computer Sciences for work on the 10-year IT modernisation program of the NHS.

The NHS's National Program for IT calls for digitising patient records, and an electronic booking and prescription system for 50 million people in its network.

iSoft has been under scrutiny for its role in the program, viewed as one of the largest IT projects in the world. In January, iSoft announced a delay in delivering its products.

"Discussions to facilitate a rescheduling of the contractual delivery schedule are ongoing," an iSoft statement said.

In March, Accenture said it expected future losses of £250m due to its NHS contracts. Accenture partly blamed significant delays by one "major subcontractor" in the second quarter in delivering what it termed critical software.

Richard Granger, director general of the IT program, has warned in the past that suppliers could be cut if they did not meet deadlines. Further, the NHS says suppliers are not paid until they deliver, a measure it said protects the "public purse."

NHS and iSoft officials could not be reached for comment early today.

Last week, iSoft announced changes to how it recognises revenue in its accounting policy. The new accounting method would cut iSoft's predicted pre-tax profits for the year ending 30 April of between £3m to £7m, down from between £17m to £22m.

Its projected revenue was revised for the same period from £210m-£215m down to £195m-£200m. The results will be announced 11 July.