At the event, Nadella is expected to speak about Microsoft's "mobile-first, cloud-first" strategy. Cloud-based Office software for the iPad would fall under both those categories.
The upcoming Office for iPad is expected to be very similar to the version of Office that Microsoft released for the iPhone last summer.
Office for iPad is expected to support Word, Excel and PowerPoint. Users will be able to create and edit documents, according to the Verge, though a subscription to Microsoft's Office 365 cloud service will be required for editing.
Microsoft could not be reached for comment.