BRIGHTON — The Archdiocese of Boston has released two decrees of suppression and one letter of extension for three of the 18 parishes that were set to close between mid-November and mid-January.

Archbishop Seán P. O’Malley met with pastors from churches closing in the upcoming months on Nov. 11 and offered them the opportunity to delay closure.

Six extensions had been previously granted. One — for Our Lady of Mercy Parish in Belmont — extended the date of closure from Nov. 18 to Dec. 31. The decree for that parish has now been released, stating that the parish territory and canonical records will go to St. Luke Parish in Belmont.

The second decree released this week announces the suppression of Sacred Heart Parish in Natick, which will close on Dec. 26. The territory and canonical registers will go to St. Patrick Parish in Natick.

The goods and obligations of both parishes will become the goods and obligations of the archdiocese.

Immaculate Conception Parish in Cambridge received a letter of extension this week and will now close Jan. 9, 2005.

The decision to offer temporary reprieves was made in consultation with the External Reconfiguration Review Committee appointed in October.

The archbishop has made similar decisions to change reconfiguration in other parts of the archdiocese. In October, he delayed closing of St. Mary of the Angels in Roxbury and St. James Parish in Stoughton. Another Stoughton parish, Our Lady of the Rosary Parish, was to be the receiving parish for St. James. On Nov. 22, the archdiocese asked parishioners from both parishes to recommend which parish would close. The parishes have made their recommendation but will not release any information about it until they have received a decision from the archdiocese.

The archbishop also announced in October a new plan for reconfiguration in Charlestown. The three Charlestown parishes will be combined into one. A priest from Lawrence, Father James Ronan, has been appointed pastor at two of those parishes.

It is estimated that in reconfiguration 83 parishes will be suppressed, eight will be created and eight churches will remain open as worship sites.