The value of the two deals wasn't disclosed, nor did Nissan detail its plans to restart some internal IT work as part of the two announcements.

The automaker, which has about 25,000 end users in North America, 'probably outsourced too much' to IBM in the first place, Greenberg said. 'I think this is something that goes back and forth within the IT world when you're outsourcing: How much?'

He added that in his view, the commodity elements of IT should be outsourced but 'the value-generation elements ... really need to be very close to your business.'

As a result of the shift in strategy, Nissan's IT department is hiring. Greenberg also has to bring in new workers to fill the positions of people who have decided not to relocate to Nashville. He declined to disclose the number of employees he expects to add in IT, saying only that it likely will be 'significant.'

Multisourcing is becoming more prevalent as companies adopt a best-of-breed approach to outsourcing. In the biggest example thus far, General Motors Corp. in February announced outsourcing contracts with six vendors that shifted some of its IT work away from Electronic Data Systems Corp. and specified standard IT processes for all of the companies to follow.