In what is sure to be hailed as a major victory for Google and a devastating loss for Amazon, Apple has reportedly decided to leave Amazons cloud storage Web Services and sign a contract worth upwards of $400m (£275m) with Google.

While Apple will still make use of Amazon Web Services (AWS), the budget it spends with the online retailer could be cut by as much as half. Apple uses AWS, along with Microsofts Azure cloud services, to support part of its own iCloud services.

The deal with Google will be celebrated by Diane Greene, who was promoted to head Googles fledgling cloud-computing business only four months ago, and who has also secured AWS-user Spotify as a new Google customer in that time.

According to CRN, the deal will be worth between $400m and $600m to Google, although its not clear if this is an annual spending rate or a set amount of capacity, and its also not been confirmed if Amazon will see an equivalent reduction in revenue.

Looking at Googles Q4 2015 results, its revenues for its Infrastructure-as-a-Service and Platform-as-a-Service products only came in at $300m, around 15 per cent of what Amazon saw in the same period. The new contract with Apple will make a massive difference to that figure.

While Google and Apple are traditionally seen as rivals, particularly when it comes to their dominant mobile operating systems, the competitive nature of the public cloud market, which is seeing intense pricing pressure, especially in computing and storage services, often leads to strange bedfellows.