CORRECTED-UPDATE 1-Microsoft to take site-by-site approach to U.S. office reopening

(Corrects headline and first sentence to reflect that Microsoft will evaluate U.S. work sites individually instead of indefinitely pushing back the date of all U.S. office reopenings. Removes reference to Apple in paragraph 4 to reflect that the company has not made vaccines mandatory for U.S. workers.)

Sept 9 (Reuters) - Microsoft Corp on Thursday said it will no longer target a specific date for reopening all of its U.S. offices and instead will reopen each site based on whether it meets a set of company criteria and local health guidelines.

"Given the uncertainty of COVID-19, we've decided against attempting to forecast a new date for a full reopening of our U.S. work sites in favor of opening U.S. work sites as soon as we're able to do so safely based on public health guidance," Microsoft said in a blog post.

Microsoft had earlier said it will open its Redmond headquarters as well as other U.S. offices on Oct. 4.

Some big tech firms are delaying a return to office, while others like Facebook Inc are making vaccinations mandatory due to the spike in COVID-19 cases in the country.

The software giant said it will also give a 30-day transition period that provides time for employees to prepare before getting back to offices. (Reporting by Tiyashi Datta in Bengaluru; Editing by Arun Koyyur)