diff --git a/src/Api/Enum/OrderMergeMode.php b/src/Api/Enum/OrderMergeMode.php
new file mode 100644
index 0000000..ee04d78
--- /dev/null
+++ b/src/Api/Enum/OrderMergeMode.php
@@ -0,0 +1,9 @@
+<?php
+
+namespace Baselinker\Api\Enum;
+
+enum OrderMergeMode: string
+{
+    case TechnicalMerge = 'technical_merge';
+    case IntoMainOrder = 'into_main_order';
+}
diff --git a/src/Api/Request/Orders.php b/src/Api/Request/Orders.php
index d1f6ec7..c31248d 100644
--- a/src/Api/Request/Orders.php
+++ b/src/Api/Request/Orders.php
@@ -3,6 +3,7 @@
 namespace Baselinker\Api\Request;
 
 use Baselinker\Api\Client;
+use Baselinker\Api\Enum\OrderMergeMode;
 use Baselinker\Api\Response\Response;
 
 class Orders extends Client
@@ -260,6 +261,22 @@ public function addOrderBySplit(int $orderId, array $itemsToSplit, ?float $deliv
         );
     }
 
+    public function setOrdersMerge(
+        int $mainOrderId,
+        array $orderIdsToMerge,
+        OrderMergeMode $mergeMode = OrderMergeMode::TechnicalMerge,
+        bool $sumDeliveryCosts = false
+    ): Response {
+        return new Response(
+            $this->post('setOrdersMerge', [
+                'main_order_id' => $mainOrderId,
+                'order_ids_to_merge' => $orderIdsToMerge,
+                'merge_mode' => $mergeMode->value,
+                'sum_delivery_costs' => $sumDeliveryCosts,
+            ]),
+        );
+    }
+
     public function getInvoiceFile(int $invoiceId): Response
     {
         return new Response(