New union election rules proposed by the National Labor Relations Board and supported by unions representing employees of private colleges have run into opposition from business interests at NLRB hearings, according to a transcript and an account of board proceedings published by The Hill, a newspaper covering Congress. Business representatives told the NLRB that its proposal to streamline union elections would leave employers too little time to respond to workers’ efforts to unionize. Several academic experts on unionization testified during the hearings, held Monday and Tuesday. But the only speaker to discuss efforts to unionize private-college employees was David Linton, a professor of communication arts at Marymount Manhattan College and president of the New York conference of the American Association of University Professors. He said administrators at his college had obstructed and prolonged a staff vote on unionization three years ago in an unsuccessful attempt to keep workers there from organizing.