Microsoft plans to release Office 2007 Service Pack 1 via the company's automatic update service starting June 16.

The advanced announcement is a result of the software maker's promise to give at least a 30-day notice before making Office service packs available through Microsoft Update, which is a part of Windows Vista and Windows XP, the company said in its Office Sustained Engineering blog.

Microsoft released Office 2007 SP1 five months ago as a download on the company's Web site. Over that time, Microsoft claims to have had tens of millions of downloads and "a very good reaction" from customers.

Microsoft said the automatic update would be rolled out gradually to ensure that the service's infrastructure can handle distribution of the software. "Think of the 16th as the earliest possible start of distribution and that no sooner than that date will SP1 start to become available to customers' systems via this channel," the company said.

The strategy of rolling out service packs in phases gives the market plenty of time to evaluate the software and gives Microsoft time to address specific customer concerns, the company said. Microsoft used the same strategy with Service Pack 3 for Office 2003.

Among the new technologies in Office 2007 is a controversial new document format called Office Open XML, which was approved last month as an open standard by the International Organization for Standardization.

The ISO's action sparked an outcry from critics who claimed Microsoft stuffed local voting committees with supporters of OOXML, an allegation the company denies. The ISO said 75% of its member nations voted to approve OOXML as a standard, 14% voted against the format, while the rest abstained, the ISO said.