SCIENCE / TECHNOLOGY

A group led by the Pritzker family of Chicago has cuts its stake in Gradco Systems Inc. of Irvine from 7.1% to 4.5%, according to a filing with the Securities and Exchange Commission.

Gradco, an Irvine manufacturer of sorters and collators for office copiers, said it sold 171,500 Gradco shares between July 28 and Sept. 27 at prices between $16.19 and $16.87 per share. The Pritzker family now owns 288,200 shares, the filing shows.

The company announced last week that Keith Stewart, Gradco’s chairman, and a group of company managers were considering a leveraged buyout of Gradco. The group said it had not yet made a formal acquisition offer to Gradco’s board of directors.

The company made the announcement in response to unusually heavy trading in its stock.