Updated from 5:44 p.m. EST Nortel's ( NT) chief financial officer resigned Monday after the company told regulators that he had traded mutual funds holding the company's stock, during investment blackout periods. The Toronto-based networking-equipment maker said Terry Hungle, whom it named financial chief late last year, would be supplanted as acting CFO by CEO Frank Dunn. Nortel said it would search for a new financial chief, and emphasized that Hungle's trades had no impact on its business or operations. The departure comes as the fallout from the Enron scandal continues to reverberate through the market. Accounting rumors have increasingly moved stocks in recent weeks, prompting executives at a number of companies to go out of their way to say their accounting and disclosure practices are appropriate. The notion that executives and directors often receive preferential treatment when it comes to their stock holdings has become particularly widely held in the wake of the Enron fiasco. After rising 55 cents to $6.84 during regular trading Monday, Nortel shares were halted after hours.