Two recent court decisions in cases in which companies suing their banks after their business accounts were looted by online fraudsters underscore the need for banking regulators to expedite new guidance on authenticating online banking transactions.

As the incidence of online fraud increases rapidly, banks' liability concerns were assuaged on May 27 when a Maine court sided with Ocean Bank, deciding that it was not liable for more than $300,000 in fraudulent transfers out of Sanford, Maine-based Patco Construction Co.'s business account.

On Monday, however, a Michigan court decided that Dallas-based Comerica Bank must reimburse Experi-Metal Inc. for $561,000 the company lost when fraudsters used wire transfers to move funds to accounts in Russia, China and other havens.