Undertakings carrying out the operations referred to in 1° of Article L. 310-1 and the supplementary occupational pension funds referred to in Article L. 381-1 may, under the conditions set out in Article A. 132-3, guarantee in their contracts a total amount of technical interest and bonuses which, in relation to the fraction of the mathematical provisions of the said contracts on which the guarantee takes effect, will not be less than guaranteed minimum rates.