DUBAI, United Arab Emirates (AP) — Stockholders at two Abu Dhabi banks approved a plan Wednesday to merge the firms into the biggest bank of all Gulf Arab countries with assets of $178 billion amid a regional economic slump. "The overwhelming vote of support from FGB and NBAD shareholders to approve this historic merger is a clear testament to the compelling rationale and value proposition for creating a bank with the financial strength, scale and expertise to deliver benefits for our customers, our shareholders and for the wider UAE economy," Sheikh Tahnoon said in a statement. NBAD's pro-forma credit profile will benefit from greater business diversification, stronger profitability and capital metrics, while FGB's depositors and senior creditors will be transferred to NBAD, a larger and fundamentally stronger entity. In June, Abu Dhabi's crown prince, Sheikh Mohammed bin Zayed Al Nahyan, ordered sovereign wealth funds Mubadala Development Co.