Waste Management Inc. posted lower net income for its fourth quarter but still higher for the year.

Houston-based Waste Management said in a news release that net income for the quarter ended Dec. 31 fell 5.3 percent to $266 million, or 58 cents per diluted share, compared with $281 million, or 59 cents per diluted share, in the 2010 period.

Waste Management said excluding certain items that affected both years, net income would have totaled $289 million for the 2011 fourth quarter compared with $287 million in the year-ago period. The 2011 fourth quarter included a $16 million after-tax charge for a litigation loss and a $7 million after-tax charge for asset impairments, restructuring charges and integration costs related to the purchase of Oakleaf Global Holdings.

Revenues for the 2011 quarter climbed 6.9 percent to $3.41 billion compared with $3.19 billion in 2010. The 2011 fourth quarter revenue included $145 million coming from the acquired Oakleaf.

For 2011, Waste Management’s net income inched up 0.8 percent to $961 million, or $2.04 per diluted share, compared with $953 million, or $1.98 per share, in 2010. Revenues advanced 6.9 percent to $13.4 billion compared with $12.5 billion for 2010. The Oakleaf purchase accounted for $251 million of the growth.

“We had a very good fourth quarter,” said David Steiner, president and chief executive officer of Waste Management. “Our core collection, landfill, and transfer station businesses performed well. We continued to see volumes improve sequentially and we had internal revenue growth from yield of 1.4 percent. We also saw accelerated improvement in our cost reduction initiatives.”

Steiner said he expects earnings to fall in the year-to-year comparison for the first quarter of 2012, “but the rest of the year should show steadily increasing improvement.”

The company is estimating full-year adjusted earnings to be in the range of $2.22 to $2.30 per diluted share. Waste Management expects results to be down in 2012 compared with 2011 for recycling commodity sales prices and waste-to-energy operations.