REYKJAVIK (Reuters) - Two former executives at an Icelandic bank which collapsed in the 2008 financial meltdown were sentenced to jail on Friday for fraud which led to a 53 million euro loss, in the first major trial of Icelandic bankers linked to the crisis. All three of the small North Atlantic island's top banks collapsed in quick succession in October 2008 due to big debts incurred during a rapid overseas expansion. Glitnir was the first to fall after the collapse of Lehman Brothers caused international credit markets to freeze up.