CLEVELAND, Dec. 1, 2010 /PRNewswire-FirstCall/ -- Lincoln Electric Holdings, Inc. (Nasdaq: LECO) will present at the NASDAQ OMX 25th Investor Program being held in London on Wednesday, December 8, 2010, at 11:15 a.m. GMT (6:15 a.m. ET). Vincent K. Petrella, SVP and Chief Financial Officer, will pres