Barrett Business Services Inc. (NASD: BBSI) rebuffed a shareholder group’s new plans for a special meeting to elect new board members, replacing the present directors. The group had announced new plans last week for a special meeting on March 13. The group said it owns more than 25 percent of outstanding shares, and it reported company bylaws allow for those owning 25 percent to call a special meeting. The group includes Kimberly Sherertz, the widow of former Barrett Chairman and CEO William Sherertz.

However, the company reported today that it calculates the group owns less than 25 percent of outstanding shares and that the group apparently miscalculated its percentage of ownership.

 The Barrett “board is fully prepared to call a special meeting,” said Chairman Anthony Meeker. “However, the company cannot be expected to call a special stockholders meeting on behalf of a particular stockholder that has not been validly requested under applicable law and the company’s bylaws. In addition, the board notes the substantial cost, management time and distraction from business operations that would be caused by a contested special meeting. When Ms. Sherertz and her group provide evidence of sufficient share ownership and voting entitlement and comply with any other legal requirements, we will move ahead promptly to call a special meeting.”

The shareholder group originally requested a special meeting on Feb. 21, but that was rejected by the company.

The group seeks to replace all board members except for Mike Elich, who also serves as CEO. The group would also add a new board slot.

Barrett ranks No. 39 on Staffing Industry Analysts’ 2011 list of largest U.S. staffing firms. The Vancouver, Wash.-based firm provides staffing and professional employer organization services.