Dow Jones Industrial Average Index erased some of last week gains on Monday, as investors turned their attention to developments in Greece. The blue chip index gave up 0.13% or 17.10 points and finished at 12,845.13 with 6 of 9 sectors posting loss. Boeing Co. tumbled 1.2% on reports the company found a technical issue in its 787 Dreamliner. The aircraft manufacturer claimed there was no safety concern and problem will be fixed soon. Among winning stocks were Bank of America and Procter & Gamble adding 1.7% and 1.2% respectively.