TORONTO, Feb. 12 -- Nortel Networks' chief financial officer has resigned amid questions about personal investments he made in a company 401(k) retirement plan just ahead of corporate announcements that caused significant swings in the company's stock price. Terry Hungle, who was named CFO late last year, allegedly transferred about $78,500 from a stock fund invested primarily in Nortel shares to a fixed-income fund last March, prior to the company's announcement that it would cut 5,000 jobs and would not meet reduced profit forecasts, Nortel said in a statement released after the close of markets Monday. Nortel's stock fell 16 percent March 28, the first trading session after the announcement. Hungle then transferred $86,300 from the fixed-income fund to the stock fund in December, when Nortel said it would lose less than expected during the fourth quarter, the company said. The shares rose 13 percent between Dec. 20 and Dec. 24, the next trading day after the announcement.