About 100 lawyers and financial advisors of creditors of Nortel Networks Corp. participated in a lengthy mediation in Toronto to try for the third time to divide $9 billion among the creditors of Nortel’s Canadian, U.S. and European entities and units, which involve numerous pension funds and disabled workers, along with bondholders, trade creditors and governments. Canadian creditors alone have filed more than $36 billion in claims. Nortel filed for bankruptcy in 2009 in Toronto, Delaware, the U.K....