Microsoft chief exceutive Steve Ballmer has announced that Citigroup is planning to upgrade as many as 500,000 of its PCs to Windows Vista in the next 13 to 14 months.
The US financial services company is in the middle of a massive IT restructuring, with 17,000 layoffs expected.
Ballmer dismissed reports that a large number of US government agencies had forbidden a move to Microsoft's new operating system. "Vista has certainly not been banned in many government departments," he said. "I'm involved in a number of accounts where I expect to see deals signed in the next couple of months."
Public sector adoption was "about the same as the corporate uptake" of Vista, Ballmer said. He cited Citigroup's plans to upgrade 500,000 computers to the new operating system.
Ballmer may be referring to not widely circulated information from the mid-January business launch of Vista. During the launch event, a top Citigroup IT executive, Jagdish Rao, said the company plans to begin rolling out Vista "on a large scale" starting in July to its 350,000 desktop PCs.
A Citigroup spokeswoman verified that the financial firm plans to begin rolling out Vista this July to the desktop PCs of all 325,000 employees. She did not comment on how long the migration is expected to take, or whether Citigroup also plans to update its employees' laptop computers.
Citigroup is rolling out Vista even as it plans to lay off 17,000 workers and outsource more of its IT operations in order to save $10bn (£5bn) over the next three years.
Microsoft, which plans to spend $500m (£250m) in 20 countries to market Windows Vista, has given seemingly conflicting predictions on Vista's closely watched uptake.
Microsoft said late last month that it had sold 20m Vista licences in its first month of general availability, putting it at more than double the pace of Windows XP. Ballmer has said he expects Vista to ship 90 million PCs this year.
At the same time, Ballmer has also dampened outside expectations, especially from Wall Street around Vista's uptake. Despite those bullish comments, Ballmer, in response to an audience member's question, also said: "I'm not arguing with the idea that it [Vista adoption] has not been fast, it's just not that much different" from other operating system releases.