For the six month period ended June 30, 2012, net income was $84.6 million, up from net income of $77.5 million for the same period last year. Net income in the first half of 2011 included net gains of $6.1 million on the sales of investment securities which was offset by a litigation settlement of $9.0 million. Diluted earnings per share were $1.85 for the first half of 2012, up from diluted earnings per share of $1.62 for the first half of 2011. The year-to-date return on average assets was 1.24 percent, up from 1.21 percent for the same six months in 2011. The year-to-date return on average equity was 16.73 percent, up from 15.36 percent for the six months ended June 30, 2011. The efficiency ratio for the first half of 2012 was 57.57 percent compared with 59.84 percent in the same period last year.
Net interest income, on a taxable equivalent basis, for the second quarter of 2012 was $97.9 million, down $2.1 million from net interest income of $100.0 million in the first quarter of 2012 and essentially flat with the second quarter of 2011. Net interest income for the first half of 2012 was $197.9 million compared with net interest income of $198.0 million for the first half of 2011. Analyses of the changes in net interest income are included in Tables 8a, 8b, and 8c.
The net interest margin was 2.98 percent for the second quarter of 2012, an 8 basis point decrease from the net interest margin of 3.06 percent in the first quarter of 2012 and an 18 basis point decrease from 3.16 percent in the second quarter of 2011. The net interest margin for the first six months of 2012 was 3.02 percent compared with 3.20 percent for the same six-month period last year primarily due to increased levels of liquidity and lower yields on loans and investment securities.