diff --git a/stock_available_to_promise_release/models/stock_move.py b/stock_available_to_promise_release/models/stock_move.py
index 33471f9fbe..d59d90eb59 100644
--- a/stock_available_to_promise_release/models/stock_move.py
+++ b/stock_available_to_promise_release/models/stock_move.py
@@ -765,3 +765,56 @@ def _get_new_picking_values(self):
         values = super()._get_new_picking_values()
         values["release_policy"] = values["move_type"]
         return values
+
+    def write(self, vals):
+        released_moves = self.browse()
+        if self.env.context.get("in_merge_mode") and "product_uom_qty" in vals:
+            # when a move is merged, we need to unrelease it if the quantity
+            # is changed and the move is unreleasable
+            released_moves = self.filtered(lambda m: m._is_unreleaseable())
+            # a change on the product_uom_qty on a released move with quantity
+            # partially done should not be possible. The 'safe_unrelease' flag
+            # is set to False to ensure this case is checked. Nevertheless,
+            # we should never reach this point as the merge candidates are
+            # filtered out in the method _update_candidate_moves_list to never
+            # merge releaseable moves with partially done quantity.
+            released_moves.unrelease(safe_unrelease=False)
+        ret = super().write(vals)
+        if released_moves:
+            released_moves.release_available_to_promise()
+        return ret
+
+    def _is_mergeable(self):
+        self.ensure_one()
+        return self.state not in ("done", "cancel") and (
+            self.picking_type_id.code != "outgoing" or self.unrelease_allowed
+        )
+
+    def _update_candidate_moves_list(self, candidate_moves):
+        # filter out the moves that are not unreleasable
+        res = super()._update_candidate_moves_list(candidate_moves)
+        # candidate_moves is a list of recordset of moves
+        # it contains one recordset per move to merge
+        # each recordset contains the moves that we want to merge (an item of self)
+        # and the candidate moves to merge into
+        new_candidate_moves = [
+            candidates.filtered(
+                lambda m, moves_to_merge=self: m in moves_to_merge or m._is_mergeable()
+            )
+            for candidates in candidate_moves
+        ]
+        # filter given list of moves to keep only the new ones
+        candidate_moves[:] = new_candidate_moves
+        return res
+
+    def _merge_moves(self, merge_into=False):
+        # From here any write on the moves are done in the context of a merge
+        # and we need to unrelease them if the quantity is changed
+        self_ctx = self.with_context(in_merge_mode=True)
+        if merge_into:
+            merge_into = merge_into.filtered(lambda m: m._is_mergeable())
+        return (
+            super(StockMove, self_ctx)
+            ._merge_moves(merge_into=merge_into)
+            .with_context(in_merge_mode=False)
+        )
diff --git a/stock_available_to_promise_release/tests/__init__.py b/stock_available_to_promise_release/tests/__init__.py
index 1eee41662b..35a813d9a2 100644
--- a/stock_available_to_promise_release/tests/__init__.py
+++ b/stock_available_to_promise_release/tests/__init__.py
@@ -1,3 +1,4 @@
+from . import test_merge_moves
 from . import test_reservation
 from . import test_unrelease
 from . import test_unrelease_2steps
diff --git a/stock_available_to_promise_release/tests/test_merge_moves.py b/stock_available_to_promise_release/tests/test_merge_moves.py
new file mode 100644
index 0000000000..5e08bd8642
--- /dev/null
+++ b/stock_available_to_promise_release/tests/test_merge_moves.py
@@ -0,0 +1,138 @@
+# Copyright 2024 ACSONE SA/NV
+# License AGPL-3.0 or later (http://www.gnu.org/licenses/agpl)
+
+from datetime import datetime
+
+from .common import PromiseReleaseCommonCase
+
+
+class TestMergeMoves(PromiseReleaseCommonCase):
+    @classmethod
+    def setUpClass(cls):
+        super().setUpClass()
+        delivery_pick_rule = cls.wh.delivery_route_id.rule_ids.filtered(
+            lambda r: r.location_src_id == cls.loc_stock
+        )
+        delivery_pick_rule.group_propagation_option = "fixed"
+        cls.pc1 = cls._create_picking_chain(
+            cls.wh, [(cls.product1, 2)], date=datetime(2019, 9, 2, 16, 0)
+        )
+        cls.shipping1 = cls._out_picking(cls.pc1)
+        cls._update_qty_in_location(cls.loc_bin1, cls.product1, 15.0)
+        cls.wh.delivery_route_id.write(
+            {
+                "available_to_promise_defer_pull": True,
+            }
+        )
+        cls.shipping1.release_available_to_promise()
+        cls.picking1 = cls._prev_picking(cls.shipping1)
+        cls.picking1.action_assign()
+
+    @classmethod
+    def _out_picking(cls, pickings):
+        return pickings.filtered(lambda r: r.picking_type_code == "outgoing")
+
+    @classmethod
+    def _prev_picking(cls, picking):
+        return picking.move_ids.move_orig_ids.picking_id
+
+    def _procure(self, qty):
+        """Create a procurement for a given quantity and run it.
+
+        The created procurement will have the required values required
+        to create a move mergeable with the existing ones into the same
+        shipment.
+        """
+        values = {
+            "company_id": self.wh.company_id,
+            "group_id": self.shipping1.group_id,
+            "date_planned": self.shipping1.move_ids.date,
+            "warehouse_id": self.wh,
+        }
+        self.env["procurement.group"].run(
+            [
+                self.env["procurement.group"].Procurement(
+                    self.product1,
+                    qty,
+                    self.product1.uom_id,
+                    self.loc_customer,
+                    "TEST",
+                    "TEST",
+                    self.wh.company_id,
+                    values,
+                )
+            ]
+        )
+
+    def test_unrelease_at_move_merge(self):
+        self.assertFalse(self.shipping1.need_release)
+        self.assertEqual(1, len(self.shipping1.move_ids))
+        original_qty = self.shipping1.move_ids.product_uom_qty
+        # run a new procurement that will create a move in the same shipment
+        self._procure(2)
+        self.assertEqual(1, len(self.shipping1.move_ids))
+        self.assertEqual(original_qty + 2, self.shipping1.move_ids.product_uom_qty)
+        self.assertFalse(self.shipping1.need_release)
+        # since the shipment is no more released, the picking should be canceled
+        self.assertEqual("cancel", self.picking1.state)
+
+    def test_unrelease_at_move_merge_2(self):
+        # create a negative quant to cancel teh qty to deliver
+        self.assertFalse(self.shipping1.need_release)
+        self.assertEqual(1, len(self.shipping1.move_ids))
+        original_qty = self.shipping1.move_ids.product_uom_qty
+        # run a new procurement that will create a move in the same shipment
+        self._procure(-original_qty)
+        self.assertEqual(1, len(self.shipping1.move_ids))
+        self.assertEqual(0, self.shipping1.move_ids.product_uom_qty)
+        # no more qty to deliver, the shipment and picking should be canceled
+        self.assertEqual("cancel", self.shipping1.state)
+        self.assertEqual("cancel", self.picking1.state)
+
+    def test_unrelease_at_move_merge_merged(self):
+        # Create a new shipping for the same product and date
+        # This will create a new move that will be merged with the existing one
+        # at merge time in the existing picking
+        pc2 = self._create_picking_chain(
+            self.wh, [(self.product1, 3)], date=datetime(2019, 9, 2, 16, 0)
+        )
+        shipping2 = self._out_picking(pc2)
+        shipping2.release_available_to_promise()
+        picking2 = self._prev_picking(shipping2)
+        picking2.action_assign()
+        self.assertEqual(self.picking1, picking2)
+        self.assertEqual(1, len(self.picking1.move_ids))
+
+        original_qty_1 = self.shipping1.move_ids.product_uom_qty
+        original_qty_2 = shipping2.move_ids.product_uom_qty
+
+        # pick1 and pick2 are the same
+        self.assertEqual(self.picking1, picking2)
+
+        # partially process the picking
+        move = self.picking1.move_ids
+        move.move_line_ids.qty_done = 2
+        # run a new procurement for the same product in the shipment 1
+        self._procure(2)
+
+        # the move should not be merged with the existing one since
+        # the first one is partially processed
+        self.assertEqual(2, len(self.shipping1.move_ids))
+        self.assertEqual(
+            2 + original_qty_1, sum(self.shipping1.move_ids.mapped("product_uom_qty"))
+        )
+        self.assertTrue(self.shipping1.need_release)
+
+        # the pick should still contain a move with the processed qty
+        # and the qty to do should be the one from shipping2
+        move = self.picking1.move_ids.filtered(lambda m: m.state == "assigned")
+        self.assertEqual(2, move.move_line_ids.qty_done)
+        self.assertEqual(5, move.product_uom_qty)
+
+        # if we release the ship 1 again, a new move should be created
+        # and merged with the existing one
+        self.shipping1.release_available_to_promise()
+        move = self.picking1.move_ids.filtered(lambda m: m.state == "assigned")
+        self.assertEqual(1, len(move))
+        self.assertEqual(2 + original_qty_1 + original_qty_2, move.product_uom_qty)
+        self.assertEqual(2, move.move_line_ids.qty_done)