Previously, the mainframe was hosted by CSC and an Baycorp managed the IBM pSeries Unix systems in-house.

The deal is worth A$5 million (US$3.8 million) per year over five years, but may be less than A$25 million in total, according to Baycorp Chief Information Officer Andrew Carline, who told Computerworld Australia the company is getting "good savings" with that price."IBM was competitive on price and the range of services it could offer above infrastructure management," Carline said. "[IBM] had made a lot of acquisitions in the data management space and is a company I can broaden my relationship with."

The mainframe cutover will happen this week.

Carline said he was not unhappy with CSC, which put in a "good proposal", but it couldn't offer the breadth of data management technology expertise that IBM could.

Baycorp also signed two deals with Capgemini SA around application development and management.