BRAINTREE, Mass. — The Archdiocese of Boston on Thursday announced the first phase of an overhaul that aims to strengthen parishes for a region-wide push to refill empty pews.

The restructuring will organize the archdiocese’s 288 parishes into 135 clusters, called collaboratives, that will share clergy, buildings and resources.

The archdiocese, among the largest in the country, on Thursday released the list of its first 12 collaboratives.

The remainder of the archdiocese’s parishes will be grouped together in two or three more phases over the coming years, with the last collaborative up and running by 2019.