Microsoft has begun offering its Office software suite on iPad.
New chief executive Satya Nadella made the announcement at his first event since taking over the top job at the American electronics giant.
Three separate apps are available – Word, Excel and Powerpoint – each of which has been fully optimised for tablet use.
Within hours of the unexpected announcement, Word became the most downloaded app for iPads in Apple’s app store with Excel and Powerpoint figuring third and fourth respectively.
Mr Nadella said the announcement was part of a long-term plan to enable people ‘to be productive across all devices’ with Microsoft software.
“We are not bound to one device, one place or one time,” he said.
“Job number one is to empower people to be more productive, to do more, across all these devices.
“Windows is a massive agenda for us. We will innovate.”
Research firm Gartner has predicted 271 million tablets will be sold this year – slightly less than the forecast of 277 million PCs and laptops. Apple’s iPad is currently the best selling model.
Office remains Microsoft’s primary income source, generating £9.7bn – just over 60% – of its operating profit in its last financial year.
“It was definitely a major mistake to wait (for this launch) – an example of the insular old-world thinking of Steve Ballmer and his management team that believed everything should be within a Windows ecosystem,” said Chris Green, from the Davies Murphy Group consultancy.
“In today’s multi-device environment, where Windows is no longer the all dominant platform it once was, that game plan doesn’t work anymore. The fact Microsoft is now catching up is only going to be a good thing and will be to the benefit of the Office applications.”