The Letter of Intent is not binding, and rather silly at the worst of times. An LOI by definition only registers intent to purchase, and it specifies this intent weakly, and due to its ambiguity should be avoided.
Letters of intent may be advanced in the world of commercial real estate. In some specific domestic markets (for example in principal to principal deals between upstream Petroleum traders and producers in the same country, or certain Joint venture projects) they may be found. But there is no underlying and supported standard international application for the Letter of Intent.