Open and read an Excel spreadsheet by Lazarus Using OLE

The code below works perfectly in Delphi, but when I ported to Lazarus, the code compiles without problems, but at the time of execution an exception occurs and the program is closed.

function TFMain.AbrePlanilha(NomePlan: String): Boolean;
begin
 Try
    Result := False;
    if not FileExists(NomePlan) Then
       exit;
    Mensagem('Abrindo excel, aguarde...');
    ExcelApp := CreateOLEObject('Excel.Application'); // <- até aqui OK

    // O erro ocorre aqui abaixo.
    // ==============================================
       ExcelPlan := ExcelApp.WorkBooks.Open(NomePlan);
    // ==============================================

    Mensagem('Planilha Excel ' + NomePlan + ' aberta OK!');
    Result := True;
    Update;
 Finally
 End;

end;  

The curious thing is that the code is the same for Delphi and for Lazarus, it is included in a common use lib for both, and in Lazarus this occurs.

What am I letting go of?