SAN FRANCISCO, USA: Google Inc's Web-based email service on Thursday suffered its second technical problem in a month as users reported difficulty accessing their contacts.

The disruption, which took 2-1/2 hours to resolve, followed a two-hour outage of Google's news website this week. Earlier this month, a majority of its email users were unable to access the service for more than an hour after routers got overloaded during a routine server upgrade.

Gmail outage challenges Google engineers

The series of disruptions comes as Google tries to compete with Microsoft Corp and International Business Machines Corp by extending its services to business users -- who are likely to be less tolerant of long outages.

Reports of the latest glitch flooded the Twitter microblogging site, with users posting comments highlighting and griping about the situation.

"A problem with Google Contacts caused many Gmail users to experience slowness and degraded service for about an hour today," Google said in a statement.

Google revamps Gmail for iPhone Android

"Mail was back to full speed for everyone around 8 am Pacific and the issue affecting Contacts was resolved shortly after. We're sorry for the inconvenience."

Gmail already competes with Microsoft's Hotmail and Yahoo Inc's Web-based e-mail. Google offers its email service for free but also sells a version to businesses with extra features and technical support for $50 per user per year.

Fear of outages, in addition to security concerns, has been a reason many businesses are wary of adopting "cloud computing" technologies offered by Google as well as Salesforce.com and Amazon.com, which help deliver data and services over the Internet.

(Reporting by Alexei Oreskovic; Editing by Leslie Gevirtz and Richard Chang)