Even minor offenses would be subject to fines of as much as $25,000 under a series of new sanctions against floor-trading abuses at the Chicago Mercantile Exchange, exchange officials said. Under the new measures a member found guilty of a major offense may be expelled or suspended and fined a maximum of $250,000, the exchange said. For minor offenses, a violator may be suspended for as long as one year in addition to being fined. Under the exchange's previous rules, the maximum fine for a minor violation was $5,000. The new rules also extend the period during which an exchange member found guilty of a major offense may be excluded from one of the exchange's hearing, disciplinary or pit committees, exchange officials said. The period was extended to two years from one year.