Nortel Networks (N) has filed for protection from creditors under the bankruptcy laws, according to a bulletin from the Wall Street Journal. No details yet; there is no information on the company’s Web site, no filings with the SEC and no news releases on the move by the company. Nortel’s shares were down sharply on Tuesday on market worries that the company would not be able to make $107 million in interest payments due this week on its debt, according to a report yesterday ...