Compiled by Dean Takahashi;Times staff writer

Bigger stake: An investment group that includes Martin E. Tash and Plenum Publishing Corp. has increased its stake in Gradco Systems Inc. from about 10% to 13.3%, according to a filing with the Securities and Exchange Commission.

Tash, chairman of Plenum, bought 241,000 shares of Gradco stock between Jan. 3 and 9, the filing said. Tash and Plenum now own about 1 million shares in the printer and office copier-equipment manufacturer. The purchase is Tash’s first investment in Gradco since he won control of the company’s board in a proxy fight in October.

“It shows we have confidence in the company,” Tash said.