diff --git a/dotnet/src/SemanticKernel.Abstractions/Contents/FunctionCallContentBuilder.cs b/dotnet/src/SemanticKernel.Abstractions/Contents/FunctionCallContentBuilder.cs
index ff4f6af246e5..89c3f5bff963 100644
--- a/dotnet/src/SemanticKernel.Abstractions/Contents/FunctionCallContentBuilder.cs
+++ b/dotnet/src/SemanticKernel.Abstractions/Contents/FunctionCallContentBuilder.cs
@@ -77,7 +77,7 @@ public IReadOnlyList<FunctionCallContent> Build()
 
                 if (this._functionNamesByIndex?.TryGetValue(functionCallIndexAndId.Key, out string? fqn) ?? false)
                 {
-                    var functionFullyQualifiedName = Microsoft.SemanticKernel.FunctionName.Parse(fqn);
+                    var functionFullyQualifiedName = ParseFullyQualifiedFunctionName(fqn);
                     pluginName = functionFullyQualifiedName.PluginName;
                     functionName = functionFullyQualifiedName.Name;
                 }
@@ -170,6 +170,28 @@ public IReadOnlyList<FunctionCallContent> Build()
     /// <param name="functionCallIdsByIndex">The dictionary of function call IDs by function call index.</param>
     /// <param name="functionNamesByIndex">The dictionary of function names by function call index.</param>
     /// <param name="functionArgumentBuildersByIndex">The dictionary of function argument builders by function call index.</param>
+
+    /// <summary>
+    /// Parses a fully-qualified function name into plugin and function parts.
+    /// Tries multiple separators (".", "_", "-") since different AI connectors use different formats.
+    /// </summary>
+    private static FunctionName ParseFullyQualifiedFunctionName(string fullyQualifiedName)
+    {
+        foreach (var separator in new[] { ".", "_", "-" })
+        {
+            if (fullyQualifiedName.Contains(separator, StringComparison.Ordinal))
+            {
+                var parsed = FunctionName.Parse(fullyQualifiedName, separator);
+                if (parsed.PluginName is not null)
+                {
+                    return parsed;
+                }
+            }
+        }
+
+        return FunctionName.Parse(fullyQualifiedName);
+    }
+
     private static void TrackStreamingFunctionCallUpdate(StreamingFunctionCallUpdateContent update, ref Dictionary<string, string>? functionCallIdsByIndex, ref Dictionary<string, string>? functionNamesByIndex, ref Dictionary<string, StringBuilder>? functionArgumentBuildersByIndex)
     {
         if (update is null)
diff --git a/dotnet/src/SemanticKernel.UnitTests/Contents/FunctionCallBuilder/FunctionCallContentBuilderTests.cs b/dotnet/src/SemanticKernel.UnitTests/Contents/FunctionCallBuilder/FunctionCallContentBuilderTests.cs
index e214478ce657..11c8c6907805 100644
--- a/dotnet/src/SemanticKernel.UnitTests/Contents/FunctionCallBuilder/FunctionCallContentBuilderTests.cs
+++ b/dotnet/src/SemanticKernel.UnitTests/Contents/FunctionCallBuilder/FunctionCallContentBuilderTests.cs
@@ -212,6 +212,48 @@ public void ItShouldCaptureArgumentsDeserializationException(JsonSerializerOptio
         Assert.NotNull(functionCall.Exception);
     }
 
+    [Fact]
+    public void ItShouldParseUnderscoreSeparatorForOllamaAndGeminiConnectors()
+    {
+        // Arrange - Ollama/Gemini use underscore (e.g. time_ReadFile) per FullyQualifiedAIFunction
+        var sut = new FunctionCallContentBuilder();
+
+        // Act
+        var update1 = CreateStreamingContentWithFunctionCallUpdate(choiceIndex: 1, functionCallIndex: 0, callId: "call_1", name: "time_ReadFile", arguments: null);
+        sut.Append(update1);
+
+        var update2 = CreateStreamingContentWithFunctionCallUpdate(choiceIndex: 1, functionCallIndex: 0, callId: null, name: null, arguments: "{\"filePath\":\"d:/test.txt\"}");
+        sut.Append(update2);
+
+        var functionCalls = sut.Build();
+
+        // Assert
+        var functionCall = Assert.Single(functionCalls);
+        Assert.Equal("call_1", functionCall.Id);
+        Assert.Equal("time", functionCall.PluginName);
+        Assert.Equal("ReadFile", functionCall.FunctionName);
+        Assert.NotNull(functionCall.Arguments);
+        Assert.Equal("d:/test.txt", functionCall.Arguments["filePath"]);
+    }
+
+    [Fact]
+    public void ItShouldParseDotSeparatorForFunctionChoiceBehavior()
+    {
+        // Arrange - FunctionChoiceBehavior uses dot (e.g. time.ReadFile)
+        var sut = new FunctionCallContentBuilder();
+
+        // Act
+        var update = CreateStreamingContentWithFunctionCallUpdate(choiceIndex: 1, functionCallIndex: 0, callId: "call_1", name: "time.ReadFile", arguments: null);
+        sut.Append(update);
+
+        var functionCalls = sut.Build();
+
+        // Assert
+        var functionCall = Assert.Single(functionCalls);
+        Assert.Equal("time", functionCall.PluginName);
+        Assert.Equal("ReadFile", functionCall.FunctionName);
+    }
+
     private static StreamingChatMessageContent CreateStreamingContentWithFunctionCallUpdate(int choiceIndex, int functionCallIndex, string? callId, string? name, string? arguments, int requestIndex = 0)
     {
         var content = new StreamingChatMessageContent(AuthorRole.Assistant, null);