Citigroup (C) earned $1.2 billion in the fourth quarter, or 38 cents a share, down 8% from about $1.3 billion, or 43 cents a share, one year earlier.

Revenue for the three months ended Dec. 31 slid to $17.2 billion from $18.4 billion a year earlier. Zacks Equity Research estimated Citi earnings for the fourth quarter would hit 50 cents a share.

For the full year, the banking giant earned $11.3 billion, up about 6.6% from $10.6 billion in 2010. Revenue fell 9% to $78.4 billion from $86.6 billion in 2010, driven by a $6.4 billion fall in Citi Holdings revenues.

The bank cut its loan loss reserve to $1.5 billion, down from $2.3 billion a year earlier. Tier 1 capital ratio stood at 13.6% in the fourth quarter, compared to 2.9% a year earlier.

“Overall, we made solid progress in 2011,” Chief Executive Vikram Pandit. “Clearly, the macro environment has impacted the capital markets and we will continue to right-size our businesses to match the environment. With Citi Holdings assets at 12% after the transfer of retail partner cards to Citicorp, we are increasingly focused on driving earnings through our core franchise and beginning to return capital to our shareholders this year.”

Write to Justin T. Hilley.

Follow him on Twitter @JustinHilley.