OKLAHOMA CITY, July 19, 2011 /PRNewswire/ -- BancFirst Corporation (NASDAQ GS: BANF) reported net income of $10.1 million or $0.65 diluted earnings per share for the second quarter of 2011 and $21.5 million or $1.37 diluted earnings per share for the six months ended June 30, 2011. These results com