The Treasury wants good causes to benefit from unclaimed cash

An account becomes dormant if there has been no activity for several years and the account holder has lost touch.

Chancellor Gordon Brown has said that he wants to redirect cash in dormant accounts to good causes.

Halifax said it will advertise to alert holders of 110,000 dormant accounts, containing deposits worth �44m, to the potential threat to their cash.

"Our job is to reunite as many customers as possible with their cash. We are using every means at our disposal to do so - mailings, advertising and the internet," Mike Regnier, head of savings at Halifax, said.

In addition, Halifax said it may employ third-party search agents to actively seek customers with more than �1,000 held in dormant accounts.

Halifax is the first big High Street bank to launch an awareness campaign of this type.