IBM has filed a lawsuit to prevent former senior executive Joanne Olsen from taking a job with rival Oracle Corp , which wooed her away from IBM after 31 years with the company.

Oracle Chief Executive Larry Ellison hired Olsen away from IBM as the rivalry between the two companies intensified following Oracle's $5.6 billion acquisition of Sun Microsystems in January. That deal brought Oracle into competition with IBM in servers and storage, areas where Ellison says he intends to overtake IBM.

IBM alleges that Olsen, a general manager in its services division, violated the terms of non-competition agreement, which requires her to wait a year after leaving IBM before taking a job with a competitor.

The lawsuit, which came to light on Thursday, was filed in New York State court on June 16.

Joanne Olsen possesses valuable confidential information about IBM and our operations. As a result, she cannot undertake a senior position at Oracle without violating her obligations to IBM, said IBM spokesman Doug Shelton.

Olsen declined comment. Her lawyer could not be reached. Officials with Oracle could not be reached.

The case is IBM vs Joanne Olsen, 15412-10, New York State Supreme Court, County of Westchester.

(Reporting by Jim Finkle. Editing by Robert MacMillan)