The borough is being urged to send messages of support to the people of Nice following the Bastille Day atrocity.
Eighty-four people died when an attacker ploughed a lorry into people on Thursday.
Eighty-five remain in hospital, 18 of them in critical condition.
“The events that unfolded in Nice on Thursday evening have left us all shocked and troubled,” said the Mayor of Causeway Coast and Glens, Alderman Maura Hickey.
“I send my sincere sympathies to the people of Nice, particularly those injured and the families and friends of those who lost their lives in this attack.”
She said that she was opening a number of books of condolence “in order to give the people of Causeway Coast and Glens the opportunity to express their heartfelt sympathies to the victims of the attack.”
The books are open at: Council Headquarters, Cloonavin, Coleraine; Ballycastle Council Offices, Sheskburn House; Limavady Council Offices, Connell Street; Coleraine Town Hall; and Ballymoney Town Hall. They can be signed during office hours, Monday to Friday, 9am-5pm. Six people are being held in connection with the killings.