Analyst company Gartner has warned that Microsoft's recent delay to the next edition of Office could take the update just out of the reach of many Software Assurance subscribers.

Software Assurance gives companies the automatic right to any update released during the subscription period, typically three years, but doesn't guarantee that any particular software will be released during the contract period. Last month Microsoft announced that Office 2007 will be available to volume licensing customers in October 2006, three years and one month after Office 2003's volume-licensing launch.

"This is the first time that the Office release cycle has exceeded three years - which raises concerns among some users who assumed that they would receive rights to a new version during the term of their agreement, based on previous Office release cycles, but may not," said Gartner analysts Alvin Park and Michael Silver in a research note on Friday. For these users, Software Assurance may seem of "marginal value", said Park and Silver.

Many Software Assurance subscribers will have received two versions of Office, XP and 2003, under their three-year plans, Gartner said. But some unlucky companies - those who renewed Software Assurance Enterprise Agreements or Select Agreements in September 2003 - already had rights to Office 2003 under their previous agreements, and won't get Office 2007 under their current agreements.

In other words, those customers won't have received a single Office upgrade for the entire term of their three-year agreement, Gartner said. "You paid SA for 36 months, but did not acquire rights to a new version," said Silver and Park. "You will have to renew SA for another three year term to receive rights to Office 2007."

They recommended these customers to lobby Microsoft to make an exception and give them rights to the Office 2007 upgrade. However, Gartner is also warning customers not to expect Microsoft to budge, since exceptions would tarnish the reputation of Software Assurance.

Microsoft said Software Assurance is a maintenance programme, and as such, doesn't guarantee particular upgrades. The company said it wouldn't be making exceptions.