Greece's National Bank run a successful sale of 750 million euro worth (1.03 billion U.S. dollars) five-year bonds on Thursday securing a 4.5 percent return of issue, according to an official announcement. The country has only returned to international financing markets earlier this month for first time since the start of the debt crisis in 2010. The bond sale by Greece's largest lender was completed within a few hours and the book building process was oversubscribed three times, the announcement said. The fact that the borrowing cost was lower than the about 5 percent yield secured for the sale of 3 billion euro worth Greek state bonds on April 10 was welcomed by bank officials and analysts as a vote of confidence in the bank and Greece's banking system and overall economy. They noted that usually bonds issued by banks have higher yields compared to state bonds. Greece was shut out of international bond markets for four years and relied on rescue loans from European counterparts and International Monetary Fund to keep afloat, fix its fiscal woes and restore growth. Through the implementation of a painful austerity and reform program which fuelled recession and protests, Greeks achieved an impressive improvement of fiscal indexes in recent months. As the achievement of a primary budget surplus opens the way for the start of talks with lenders later this year for the further reduction of the sovereign debt, the government and local banks focus on the further strengthening of the sector through bond sales and share offerings in order to boost liquidity and support the real economy. (1 euro= 1.38 U.S. dollars)