DAYTON DAILY NEWS                   Copyright (c) 1996, Dayton Newspapers Inc.DATE: Tuesday, July 2, 1996                  TAG: 9607030290EDITION: CITY           SECTION: METRO TODAY PAGE: 4B TYPE: MAJOR                    RIFFE PLEADS GUILTY TO LESSER CHARGESCOLUMBUS, Ohio (AP) - Former House Speaker Vern Riffe on Monday pleaded guiltyto two lesser charges related to an ethics investigation that marred his 20-year run as one of the most powerful officeholders in the state.   The 71-year-old Democrat who retired in 1994 pleaded guilty to two misdemeanor counts of failing to report on state financial disclosure forms interest income from an inheritance he received from his father in 1990.   But the move gives Riffe, who is writing a chronicle of his decades in the Legislature, room to argue he did nothing wrong in accepting speaking fees totaling $4,500 from subsidiaries of The Limited Inc. clothing chain.   "I said from day one that I followed the law," Riffe said in a statement released after the hearing.   George Ellis, assistant county prosecutor, said Riffe could read whatever he wanted into the plea agreement. But he noted that both the undisclosed payments from The Limited and the interest income were included in the chargesto which Riffe pleaded guilty   Franklin County Common Pleas Judge David Fais fined Riffe $500 plus court costs, then ordered him to pay the fine to a charity of Riffe's choice.LENGTH: Short :   33 LINESSUBJ: PLEA      ETHICSNA: VERN RIFFEENHANCER: REF5