Google's Gmail has suffered another disruption that prevented users from accessing their webmail, Gtalk and their contact lists.

Google gave notice of the outage at 3.30pm GMT, claiming that it only affected a small subset of users, and after two and half hours the issue had been resolved, according to Australia's IT News.

In a statement, Google said: “A problem with Google Contacts caused many Gmail users to experience slowness and degraded service for about an hour today. Mail was back to full speed for everyone around 8am Pacific and the issue affecting Contacts was resolved shortly after. We're sorry for the inconvenience.”

This is the fourth time this year that Google's webmail service has suffered from a similar problem. Gmail suffered a similar outage on the 1st September after an error during ‘routine upgrades' to the company's web servers, while back in February and March users were locked out of Gmail due to technical errors.