JPMorgan Chase is blaming "technical issues" for an outage to its online banking site that may well be one of the longest outages by a major provider in recent memory. The bank, which has $2 trillion in assets, posted a message on its portal asking customers to "log on later."

The bank said its online services were lost sometime "overnight" last night, and would not predict when they expect that the site will be restored. ATMs, branches, and telephone call centres are not affected by the outage, though call centre volume has increased, said Tom Kelly, a Chase spokesman.

The cause of the outage isn't clear, Kelly said. "It's a technical issue that we're dealing with."

Twitter postings about the outage have been fast and sometimes furious, and put various timeframes on the outage, some showing it may have started 18 hours or more hours ago. "For a bank of Chase's size to be out this long is certainly unusual - this time of the day at least," said Emmett Higdon, an analyst at Forrester Research Com.

Higdon said that most such outages are caused conjunction with new rollouts or a new vendor being brought out, said Higdon. Outages by major commercial operations aren't rare, but are usually limited to a few hours, he added.

Customer have been so sold on the idea on online functionality they are going to notice when you go down, said Higdon. If systems are "down for anything other than a short period of time would have a tremendous impact."