PORTLAND – A group of Ocean National Bank shareholders is trying to block the Maine bank’s sale to a Vermont banking group.

The shareholders met Wednesday night to organize their opposition to the $53 million merger with Chittenden Corp., which is slated for a shareholder vote Dec. 12.

It would be the Burlington, Vt., bank’s second acquisition of a Maine bank this year. Chittenden last January bought Maine Bank & Trust, the community bank launched in 1991 by philanthropist Elizabeth Noyce of Bremen.

“Underlying it all, those of us who have been in town many years like to deal with local people and like the control we have through friends and neighbors on what the bank will do and where it will go,” said John Cummings, a shareholder and certified public accountant. “There’s a group of us who feel this isn’t as wise a move as it might initially appear to be.”