The phrase “national economic interest” in the legislation is a cut and paste from the OECD code on anti-bribery.
In my understanding—and you can seek advice on this from experts—it is to distinguish national economic interest from the interest of other countries. If you're part of this group in the OECD, you cannot favour or let a company off because it helps France versus Germany, or Germany versus Italy, or Canada versus the United States.