Fourth quarter earnings decreased by 29% from a year ago. Diluted earnings per share for the fourth quarter of $0.25 represents a 24% decrease from the $0.33 reported for the fourth quarter of 2010. Now, for the year 2011, our earnings decreased by 12% and diluted earnings per share for the full year of $1.11 is a 9% decrease over the $1.22 reported in 2010. We also reported a 2% decrease in revenues from fourth quarter 2010 to fourth quarter 2011. And for the year 2011, revenues increased 3% over 2010 revenues.
Our earnings for the fourth quarter of 2010 and 2011 were affected by gains and losses attributable to the SIVs on our balance sheet, as well as the sale of other assets. Now, during fourth quarter 2011, SIVs accounted for a loss of 700 million -- $700,000, while fourth quarter 2010 -- while in the fourth quarter 2010, SIVs and the sale of other assets netted to an increase to earnings of approximately $18 million.
Now also during the fourth quarter 2011, our non-cash asset balances under management increased by $10 billion. Of that, SEI's assets under management grew by $5.7 billion during the quarter, while LSV's assets under management grew by $4.3 billion. Now, please note that the capital markets' performance, particularly at the end of third quarter 2011, had a negative impact on fourth quarter revenues in our asset management businesses.
Our Institutional Investors segment was most negatively affected due to the way that business segment calculates and takes fees. Ed Loughlin will address this issue in his comments. Now, thanks to a stronger market exiting 2011, our asset management fee should respond positively. Now, during the fourth quarter 2011, we repurchased [$3.2 million] [ph] of SEI stock at an average price of just over $16 per share. Now that translates to over $52 million of stock repurchases during the quarter.