According to the commission, the infringement took place on 17 January 2017, when Galp Gás Natural "in the last seconds of the negotiation" on a product for delivery the next day, bought tiny quantities of gas that fixed the price for the following day.

During the instruction phase of the competition law case, the commission found that Galp Gás Natural "carried out a series of abnormal behaviors", namely that it just three seconds before the close of the market, bought gas at a price 7% higher than at which it had sold gas a few minutes earlier.

The move had the goal, according to the commission, of "fixing the last daily price to an artificially high level".

The amount of the penalty provided for in the law, of €100,000, was reduced by 20% because Galp agreed to pay up voluntarily.