Microsoft’s cloud services, including Office 365, customer relationship management (CRM) suite, Dynamics CRM, experienced their first major outage for users in the US.

The outage which began at 7:30pm BST on Wednesday, lasted for around five hours. The company has not disclosed the reason behind that caused the disruption so far.

Microsoft Global Foundation Services general manager Steven Gerri said, "At approximately 11:30 a.m. PDT, Microsoft became aware of a networking issue affecting customers of some Microsoft services hosted out of one of our North American data centers."

"We apologise for the inconvenience that Office 365 outage has caused today. We are working on resolving the issue," the company said.

Microsoft launched its cloud-based service for businesses Office 365 suite on 28 June.

Microsoft Office 365 combines Microsoft Exchange Online, Microsoft Lync Online, Microsoft Office and Microsoft SharePoint Online, across 40 markets.

The Office 365 connects to Microsoft Office applications like Excel, OneNote, Outlook, PowerPoint, Word and others to offer a range of service plans designed to meet the needs of businesses of various sizes.

According to Microsoft service-level agreement, the company guarantees a 99.9% level of uptime.

The company says that if it fails to reach 99.9% uptime, users are eligible for a minimum of 25% service credit.

Last week, European cloud services run by Amazon and Microsoft were disrupted over the weekend when a lightning strike knocked out power at a Dublin data centre.

According to a service update posted on its website, Amazon’s EC2 and Relational Database Service were knocked offline. "We understand at this point that a lightning strike hit a transformer from a utility provider to one of our Availability Zones in Dublin, sparking an explosion and fire," a service update read.

Microsoft Business Productivity Online Standard Suite (BPOS) was knocked out by the Dublin lightning strike, but according to a Twitter update in the early hours of Monday morning the service was back up for all EMEA customers.