Daniel Daigneault, president and CEO of The First Bancorp, announced his intent to retire early next year from the Damariscotta-based bank.

The First’s board of directors named Tony C. McKim, president and chief operating officer, as Daignault’s eventual successor as CEO.

The bank, founded in 1864, is the 18th-oldest bank in the United States, according to a Thursday press release announcing the impending management change. Under Daigneault’s tenure, which began in 1994, the bank grew from four locations with assets of just under $200 million to 16 locations and nearly $1.5 billion in assets.

McKim joined the bank in 2005 when it merged with First National Bank of Bar Harbor where he had been president and chief executive. The First trades on the NASDAQ as FNLC. Its stock price closed at $16.03, rising 1.14 percent over the course of the day.