IBM will take Apple to court over the hiring of former IBM executive Mark Papermaster as the head of Apple's iPhone and iPod development unit.
According to IBM, because Papermaster served as vice president of IBM's blade development unit, he has had access to company secrets.
Papermaster had also signed an agreement not to work for a competitor for at least a year, IBM has said.
IBM spokesperson Doug Shelton told Reuters the company intends to "vigorously pursue" the case in court.