A new law meant to level the playing field between European companies and competitors propped up by foreign governments has created an "administrative nightmare" for those very businesses it was meant to help.

The EU's new Foreign Subsidies Regulation (FSR), which took effect last month, requires large companies active in the EU to report any financial contribution received from a government in a non-EU country in the last three years before completing a merger or participating in a large public tender worth more than €250 million.