First Interstate Bancsystem Inc. reported unaudited consolidated earnings results for the fourth quarter and year ended December 31, 2011. For the quarter, the company reported total interest income of $72,006,000 against $76,215,000 a year ago. Net interest income was $63,035,000 against $62,850,000 a year ago. Income before income tax expense was $20,060,000 against $16,038,000 a year ago. Net income was $13,265,000 against $10,838,000 a year ago. Net income available to common shareholders was $12,402,000 or $0.29 per diluted share against net income available to common shareholders of $9,975,000 or $0.23 per diluted share a year ago. Return on average common equity was 6.84% against 5.68% a year ago. Return on average common assets was 0.72% against 0.58% a year ago. Book value per common share was $16.77 against $16.05 a year ago. For the year, the company reported total interest income of $292,883,000 against $314,546,000 a year ago. Net interest income was $250,852,000 against $251,439,000 a year ago. Income before income tax expense was $66,161,000 against $54,446,000 a year ago. Net income was $44,546,000 against $37,356,000 a year ago. Net income available to common shareholders was $41,124,000 or $0.96 per diluted share against net income available to common shareholders of $33,934,000 or $0.85 per diluted share a year ago. Return on average common equity was 5.86% against 5.22% a year ago. Return on average common assets was 0.61% against 0.52% a year ago. The company reported charge-offs of $22,435,000 for the fourth quarter ended December 31, 2011 against $18,045,000 for the same quarter in 2010.