Under the plans, ANZ in New Zealand will adopt The National Bank's technology systems and the majority of its products.

The move will lead to bank the laying off 200 IT contractor roles and redployment of some full-time staff, ANZ National Bank chief David Hisco said in a conference call.

"ANZ bought The National Bank in 2003 and after almost ten years of reducing duplication, the next logical step is to combine them into one," Hisco says. "In recent years we've made things simpler for customers by creating one management structure across both banks, one customer approvals process and, very soon, we'll be moving to one set of products and The National Bank's technology system."

He says the bank will spend £100 million on rebranding branches in line with the group's corporate identity, and will close or merge branches located close to each other.

Says Hisco: "At the moment we have about 300 branches nationwide and over the next two years as we combine some of our adjacent branches, we'll end up with about 280 full-service branches."

No frontline staff will be let go as a result of the merger, Hisco says.