(Reuters) — Microsoft and Oracle on Wednesday said they reached an agreement to make their two cloud computing services work together with high-speed links between their data centers, targeting big business users and uniting against cloud computing leader Amazon.com’s Amazon Web Services.

The two companies said the high-speed link between their data centers would start with facilities in the eastern United States and spread to other regions. They will also work together to let joint users log into to services from either company with a single user name and get tech support from either company.

The move comes as both Oracle and Microsoft are courting large businesses and government customers considering moving computing tasks currently handled in their own data centers to cloud providers.

“With Oracle’s enterprise expertise, this alliance is a natural choice for us as we help our joint customers accelerate the migration of enterprise applications and databases to the public cloud,” Microsoft’s cloud chief Scott Guthrie said in a statement.

AWS, the largest cloud computing provider, is encroaching on many of those customers, including in Oracle’s historical stronghold in the database market.

“With this alliance, our joint customers can migrate their entire set of existing applications to the cloud without having to re-architect anything, preserving the large investments they