Greece Outside In: Greek yields fall as economic optimism grows

* Economic optimism boosts 10-yr Greek bonds * Diplomatic talks in Ukraine weigh on safe-haven debt * ECB meets on Thursday, widely seen leaving rates unchanged LONDON, March 6 (Reuters) - Junk-rated 10-year Greek bond yields hit near-four year lows on Thursday, driving them below those on 30-year debt for the first time since late 2013 in a sign of market confidence in the battered economy.