Republic Services Inc.‘s long-time minority owner, Cascade Investment LLC, increased its holding in the company to about 17 percent with the purchase of 1.4 million shares in December, according to a company spokesman.

Cascade, of Kirkland, Wash., now controls about 65 million shares of Phoenix-based Republic’s stock, says Will Flower, senior vice president of communications for the company, in an interview.

Cascade has been a Republic investor for more than 10 years and consistently increased its position over that time. This latest move is part of that incremental investment, Flower says.

Cascades is controlled by Microsoft Chairman Bill Gates. Cascades’ chief investment officer, Michael Larson, sits on Republic’s board of directors.