The popular Google (GOOG) blogging product, blogger.com, has suffered a major service disruption. The disruption was first reported on Tuesday, June 16th, and is ongoing.

This is impacting many blogs hosted on blogger.com, including popular blogs like Americablog.com and eschatonblog.com

Blogger.com offers a feature to redirect users from a blogspot URL to a custom domain name. As an example, atrios.blogspot.com is supposed to be automatically redirected to eschatonblog.com. However, starting last Tuesday, the Google product started inserting an interstitial page before redirecting.

For Firefox uses this appears as a redirect warning notifying users that they were leaving Blogger. For Internet Explorer and Safari users (and iPhone users), they are notified that the page could not be displayed or that the blogs no longer exist.

Users are still able to access the blogs via the custom domain name, however any bookmarks, or links from other sites, using the blogspot address are affected.

This has led to a significant decline in traffic for many Blogspot.com hosted blogs, with some sites reporting a 50 percent decline in traffic.

Blogger engineers acknowledged the problem on Wednesday morning, June 17th: Custom domain redirects incorrectly displaying warning page

“Custom domain users are reporting that traffic to their blog’s Blogspot URL is inserting a redirect warning notifying users that they are leaving Blogger. Previously, no warning was issued and visits to the Blogspot URL were automatically re-routed to the user’s Custom Domain.

Blogger engineers are aware of the issue and are working on a fix. We apologize for the issue, and will update this post when it is fixed.”

As of Saturday the service disruption is still unresolved.