WASHINGTON — Microsoft has collaborated with the National Security Agency more extensively than it previously acknowledged, providing the spy agency with up-to-date access to its customer data whenever the company changes its encryption and related software technology, according to a new report based on disclosures by the former N.S.A. contractor Edward J. Snowden.

Quoting classified internal N.S.A. newsletters obtained from Mr. Snowden, The Guardian newspaper reported that Microsoft had helped the security agency find ways to circumvent its encryption on its Outlook.com portal’s encrypted Web chat function, and that the agency was given what The Guardian described as “pre-encryption stage” access to e-mail on Outlook, including Hotmail e-mail.

The Guardian, which did not release the N.S.A. documents that it quoted, said that Microsoft had also provided the F.B.I. with access to its SkyDrive service, a cloud storage service with millions of users.

Microsoft, according to The Guardian, also worked with the F.B.I. to study how Outlook allowed users to create e-mail aliases, while Skype, now owned by Microsoft, worked with the government to help it collect both the video and audio of conversations. It also reported that information collected through the N.S.A. program code-named Prism was shared with both the F.B.I. and the C.I.A.