The European Central Bank's dollar facility was tapped for the first time since February on Wednesday, in another sign that money markets are in a distressed state.

A single euro zone bank borrowed $500 million worth of one-week dollars at a fixed interest rate of 1.1 percent, well above the rates that trusted banks can get dollars for on open markets.

It is the first time since February 23 that the facility has been used and comes as escalating euro zone debt tensions continue to heavily limit lending in interbank markets.