The Court of Appeal made the ruling last week Thursday when it allowed, in part, an appeal brought by Clarke.
He went on retirement in 2008 after serving the bank for 40 years.
A lengthy legal battle which followed over his entitlements was subsequently settled in 2011.
The latest dispute involves a BMW which was purchased for £260,000.
Clarke was entitled to a Five Series BMW but a Seven Series one was purchased.
An agreement was brokered between the parties in which Clarke was to pay the difference.
Clarke claimed he made the payment amounting to £41,181.
However, it later emerged that the bank failed to return the money as part of its former employee’s entitlement.
The Court of Appeal in handing down its decision ruled that in the interest of the parties, the matter should go to arbitration.
The matter has been placed before Graeme Mew of the London Court of International Arbitration for determination.