Index: ps/trunk/binaries/data/mods/public/simulation/components/Barter.js
===================================================================
--- ps/trunk/binaries/data/mods/public/simulation/components/Barter.js
+++ ps/trunk/binaries/data/mods/public/simulation/components/Barter.js
@@ -47,20 +47,6 @@
 	return prices;
 };
 
-Barter.prototype.PlayerHasMarket = function(playerID)
-{
-	var cmpRangeManager = Engine.QueryInterface(SYSTEM_ENTITY, IID_RangeManager);
-	var entities = cmpRangeManager.GetEntitiesByPlayer(playerID);
-	for (var entity of entities)
-	{
-		var cmpFoundation = Engine.QueryInterface(entity, IID_Foundation);
-		var cmpIdentity = Engine.QueryInterface(entity, IID_Identity);
-		if (!cmpFoundation && cmpIdentity && cmpIdentity.HasClass("Barter"))
-			return true;
-	}
-	return false;
-};
-
 Barter.prototype.ExchangeResources = function(playerID, resourceToSell, resourceToBuy, amount)
 {
 	if (amount <= 0)
@@ -82,15 +68,11 @@
 		return;
 	}
 
-	// This can occur when the player issues the order just before the market is destroyed or captured
-	if (!this.PlayerHasMarket(playerID))
-		return;
-
 	if (amount != 100 && amount != 500)
 		return;
 
 	let cmpPlayer = QueryPlayerIDInterface(playerID);
-	if (!cmpPlayer)
+	if (!cmpPlayer || !cmpPlayer.CanBarter())
 		return;
 
 	let prices = this.GetPrices(cmpPlayer);
Index: ps/trunk/binaries/data/mods/public/simulation/components/GuiInterface.js
===================================================================
--- ps/trunk/binaries/data/mods/public/simulation/components/GuiInterface.js
+++ ps/trunk/binaries/data/mods/public/simulation/components/GuiInterface.js
@@ -124,7 +124,7 @@
 			"researchedTechs": cmpTechnologyManager ? cmpTechnologyManager.GetResearchedTechs() : null,
 			"classCounts": cmpTechnologyManager ? cmpTechnologyManager.GetClassCounts() : null,
 			"typeCountsByClass": cmpTechnologyManager ? cmpTechnologyManager.GetTypeCountsByClass() : null,
-			"canBarter": Engine.QueryInterface(SYSTEM_ENTITY, IID_Barter).PlayerHasMarket(i),
+			"canBarter": cmpPlayer.CanBarter(),
 			"barterPrices": Engine.QueryInterface(SYSTEM_ENTITY, IID_Barter).GetPrices(cmpPlayer)
 		});
 	}
Index: ps/trunk/binaries/data/mods/public/simulation/components/Player.js
===================================================================
--- ps/trunk/binaries/data/mods/public/simulation/components/Player.js
+++ ps/trunk/binaries/data/mods/public/simulation/components/Player.js
@@ -71,6 +71,7 @@
 	this.disabledTechnologies = {};
 	this.startingTechnologies = [];
 	this.spyCostMultiplier = +this.template.SpyCostMultiplier;
+	this.barterEntities = [];
 	this.barterMultiplier = {
 		"buy": clone(this.template.BarterMultiplier.Buy),
 		"sell": clone(this.template.BarterMultiplier.Sell)
@@ -215,6 +216,11 @@
 	return Math.round(ApplyValueModificationsToEntity("Player/MaxPopulation", this.maxPop, this.entity));
 };
 
+Player.prototype.CanBarter = function()
+{
+	return this.barterEntities.length > 0;
+};
+
 Player.prototype.GetBarterMultiplier = function()
 {
 	return this.barterMultiplier;
@@ -748,7 +754,6 @@
 	if (msg.from != this.playerID && msg.to != this.playerID)
 		return;
 
-	let cmpIdentity = Engine.QueryInterface(msg.entity, IID_Identity);
 	let cmpCost = Engine.QueryInterface(msg.entity, IID_Cost);
 
 	if (msg.from == this.playerID)
@@ -756,20 +761,28 @@
 		if (cmpCost)
 			this.popUsed -= cmpCost.GetPopCost();
 
-		if (cmpIdentity && MatchesClassList(cmpIdentity.GetClassesList(), panelEntityClasses))
-		{
-			let index = this.panelEntities.indexOf(msg.entity);
-			if (index >= 0)
-				this.panelEntities.splice(index, 1);
-		}
+		let panelIndex = this.panelEntities.indexOf(msg.entity);
+		if (panelIndex >= 0)
+			this.panelEntities.splice(panelIndex, 1);
+
+		let barterIndex = this.barterEntities.indexOf(msg.entity);
+		if (barterIndex >= 0)
+			this.barterEntities.splice(barterIndex, 1);
 	}
 	if (msg.to == this.playerID)
 	{
 		if (cmpCost)
 			this.popUsed += cmpCost.GetPopCost();
 
-		if (cmpIdentity && MatchesClassList(cmpIdentity.GetClassesList(), panelEntityClasses))
+		let cmpIdentity = Engine.QueryInterface(msg.entity, IID_Identity);
+		if (!cmpIdentity)
+			return;
+
+		if (MatchesClassList(cmpIdentity.GetClassesList(), panelEntityClasses))
 			this.panelEntities.push(msg.entity);
+
+		if (cmpIdentity.HasClass("Barter") && !Engine.QueryInterface(msg.entity, IID_Foundation))
+			this.barterEntities.push(msg.entity);
 	}
 };
 
Index: ps/trunk/binaries/data/mods/public/simulation/components/tests/test_Barter.js
===================================================================
--- ps/trunk/binaries/data/mods/public/simulation/components/tests/test_Barter.js
+++ ps/trunk/binaries/data/mods/public/simulation/components/tests/test_Barter.js
@@ -61,19 +61,10 @@
 		bought = amount;
 		return true;
 	},
+	"CanBarter": () => true,
 	"GetBarterMultiplier": () => multiplier
 });
 
-AddMock(SYSTEM_ENTITY, IID_RangeManager, {
-	"GetEntitiesByPlayer": (id) => id == playerID ? [62, 60, 61, 63] : []
-});
-
-AddMock(60, IID_Identity, {
-	"HasClass": (cl) => true
-});
-
-AddMock(60, IID_Foundation, {});
-
 // GetPrices
 cmpBarter.priceDifferences = { "wood": 8, "stone": 0, "metal": 0 };
 TS_ASSERT_UNEVAL_EQUALS(cmpBarter.GetPrices(cmpPlayer).buy, {
@@ -100,15 +91,6 @@
 });
 multiplier.buy.stone = 1.0;
 
-// PlayerHasMarket
-TS_ASSERT(!cmpBarter.PlayerHasMarket(playerID));
-
-AddMock(61, IID_Identity, {
-	"HasClass": (cl) => true
-});
-
-TS_ASSERT(cmpBarter.PlayerHasMarket(playerID));
-
 // ExchangeResources
 // Price differences magnitude are caped by 99 - CONSTANT_DIFFERENCE.
 // If we have a bigger DIFFERENCE_PER_DEAL than 99 - CONSTANT_DIFFERENCE at each deal we reach the cap.
@@ -157,6 +139,7 @@
 AddMock(playerEnt, IID_Player, {
 	"TrySubtractResources": () => false,
 	"AddResource": () => {},
+	"CanBarter": () => true,
 	"GetBarterMultiplier": () => multiplier
 });
 cmpBarter.ExchangeResources(playerID, "wood", "stone", 100);
Index: ps/trunk/binaries/data/mods/public/simulation/components/tests/test_GuiInterface.js
===================================================================
--- ps/trunk/binaries/data/mods/public/simulation/components/tests/test_GuiInterface.js
+++ ps/trunk/binaries/data/mods/public/simulation/components/tests/test_GuiInterface.js
@@ -62,8 +62,7 @@
 			"buy": { "food": 150 },
 			"sell": { "food": 25 }
 		};
-	},
-	"PlayerHasMarket": function() { return false; }
+	}
 });
 
 AddMock(SYSTEM_ENTITY, IID_EndGameManager, {
@@ -114,6 +113,7 @@
 	"IsEnemy": function() { return true; },
 	"GetDisabledTemplates": function() { return {}; },
 	"GetDisabledTechnologies": function() { return {}; },
+	"CanBarter": function() { return false; },
 	"GetSpyCostMultiplier": function() { return 1; },
 	"HasSharedDropsites": function() { return false; },
 	"HasSharedLos": function() { return false; }
@@ -199,6 +199,7 @@
 	"IsEnemy": function() { return false; },
 	"GetDisabledTemplates": function() { return {}; },
 	"GetDisabledTechnologies": function() { return {}; },
+	"CanBarter": function() { return false; },
 	"GetSpyCostMultiplier": function() { return 1; },
 	"HasSharedDropsites": function() { return false; },
 	"HasSharedLos": function() { return false; }
Index: ps/trunk/binaries/data/mods/public/simulation/components/tests/test_Player.js
===================================================================
--- ps/trunk/binaries/data/mods/public/simulation/components/tests/test_Player.js
+++ ps/trunk/binaries/data/mods/public/simulation/components/tests/test_Player.js
@@ -18,6 +18,8 @@
 
 Engine.LoadHelperScript("ValueModification.js");
 Engine.LoadComponentScript("interfaces/Player.js");
+Engine.LoadComponentScript("interfaces/Cost.js");
+Engine.LoadComponentScript("interfaces/Foundation.js");
 Engine.LoadComponentScript("interfaces/ModifiersManager.js");
 Engine.LoadComponentScript("Player.js");
 
@@ -37,6 +39,10 @@
 	},
 });
 
+var playerID = 1;
+cmpPlayer.SetPlayerID(playerID);
+TS_ASSERT_EQUALS(cmpPlayer.GetPlayerID(), playerID);
+
 TS_ASSERT_EQUALS(cmpPlayer.GetPopulationCount(), 0);
 TS_ASSERT_EQUALS(cmpPlayer.GetPopulationLimit(), 0);
 
@@ -66,3 +72,29 @@
 		"metal": 1.0
 	}
 });
+
+AddMock(60, IID_Identity, {
+	"GetClassesList": () => {},
+	"HasClass": (cl) => true
+});
+AddMock(60, IID_Ownership);
+AddMock(60, IID_Foundation, {});
+cmpPlayer.OnGlobalOwnershipChanged({ "entity": 60, "from": INVALID_PLAYER, "to": playerID });
+TS_ASSERT(!cmpPlayer.CanBarter());
+
+AddMock(61, IID_Identity, {
+	"GetClassesList": () => {},
+	"HasClass": (cl) => false
+});
+cmpPlayer.OnGlobalOwnershipChanged({ "entity": 61, "from": INVALID_PLAYER, "to": playerID });
+TS_ASSERT(!cmpPlayer.CanBarter());
+
+AddMock(62, IID_Identity, {
+	"GetClassesList": () => {},
+	"HasClass": (cl) => true
+});
+cmpPlayer.OnGlobalOwnershipChanged({ "entity": 62, "from": INVALID_PLAYER, "to": playerID });
+TS_ASSERT(cmpPlayer.CanBarter());
+
+cmpPlayer.OnGlobalOwnershipChanged({ "entity": 62, "from": playerID, "to": INVALID_PLAYER });
+TS_ASSERT(!cmpPlayer.CanBarter());