[ecfisa]

Hola Santiago.

Fijate si te sirve de este modo:

Código Delphi [-]
procedure TrimRE(RichEdit: TRichEdit);
var
  i: Integer;
begin
  with RichEdit do
    if Lines.Count > 0 then
    begin
      i := Lines.Count-1;
      while Lines[i] = EmptyStr do
      begin
        Lines.Delete(i);
        Dec(i);
      end;
      Lines[i] := Trim(Lines[i]);
    end;
end;

Saludos