Tue May 21, 2013 5:09am EDT
* Focus on Ben Bernanke's testimony for hints on stimulus
* Bund losses might be limited by weak euro zone outlook
* Greek 10-year yield falls below 30-year for 1st time since 2010
By Emelia Sithole-Matarise
LONDON, May 21 (Reuters) - Greek 10-year bond yields fell below longer-dated ones on Tuesday for the first time in three years as investors priced out the risk ...