Camden National Corp., which operates 50 branches in Maine, posted lower fourth-quarter earnings due to acqusition-related costs and operating expenses of newly acquired branches.

In the fourth quarter, net income fell to $4.2 million, or 55 cents a share, down from $5.8 million, or 76 cents a share, a year ago.

For the full year ended Dec. 31, total assets grew 11 percent to $2.6 billion. Loans grew 3 percent and deposits increased 21 percent, driven by branch acquisitions.

The company recently acquired 15 Bank of America branches and divested one due to Department of Justice requirements.

“Our 2012 results were impacted by expenses associated with the branch acquisition and other costs to ramp up the branches, as well as continued pressure on net interest income and increased compliance costs,” said Camden National’s president and chief executive, Gregory Dufour.

“We continue to manage the organization over the long term by making strategic investments, such as the branch acquisition and remaining cautious in this challenging interest rate environment,” Dufour said.

Camden National’s board approved a dividend of 25 cents a share, payable on Jan. 31 to shareholders of record as of Jan. 15.