In a Tuesday announcement, the U. S. Department of the Interior (DOI) revealed that it had picked Google Apps – over the Microsoft Office 365 – for providing its nearly 90,000 employees with cloud-based email and collaboration applications.

The contract which Google has won from the Interior Department – which also includes the National Park Service – will shift the agency’s staffers from the currently-in-use "seven on-premise email systems" to the online offerings from the Internet search giant.

Going by the details shared by the DOI, the contract has actually been awarded to Google’s Ohio-based partner Onix Networking, which will be given a two-month period to prove that it can meet the various technology and security requirements of the agency. Thereafter, the agency will likely go ahead with an across-the-board roll out of the apps by December.

According to the agency, the seven-year contract – which will essentially have Google Apps for Government consolidating a horde of email systems presently being used – is valued at around $34.9 million. The agency also said that the move to switch to Google’s online services will also help it make a savings of up to $500 million by 2020.

Meanwhile, expressing disappointment at rival Google’s grabbing of the US contract, Microsoft said in a statement that it has a "positive, longstanding relationship" with the DOI, with which it is “working on a number of enterprisewide initiatives,” and added: “We will engage with our partners and DOI to review and understand the reasons for this decision” of awarding Google with the contract.