International Game Technology (IGT 0.15%) sent a letter to its shareholders on Friday urging them not to elect a trio of director candidates that dissident investor Jason Ader put forth in advance of the company's annual general meeting.

Those three candidates include former company CEO and Chairman Charles Mathewson, who the company says "engaged in questionable compensation practices, expected IGT to fund his lavish lifestyle, and exerted his influence over the Board long after retiring as Chairman in 2003."

Ader's group, which currently holds around 3% of IGT's stock, has accused the current board of losing focus on its core business and of making questionable financial decisions.

The company's annual meeting is slated to take place on March 5 in Las Vegas.