STOCKHOLM (Reuters) -Europe's car exporters are still struggling with uncertainty over U.S. tariffs despite last month's trade deal, Wallenius Wilhelmsen, the operator of one of the world's largest car-carrier fleets, told Reuters on Tuesday.

The U.S. and European Union struck a trade deal in late July that saw U.S. import tariffs on most goods from Europe, including cars, set at 15%. Cars had initially faced a 27.5% levy after U.S. President Donald Trump hiked tariffs this year.

However, the new 15% rate has not yet been implemented for cars, meaning that Wallenius customers such as BMW, Mercedes-Benz and Volvo Cars still face the higher rate.

The absence of an executive order from Trump lowering the autos tariff has left the industry holding its breath for potential last-minute changes.

"So far we actually do not know exactly what the tariff level will be. Our customers do not know either, so it is too early to say what they'll do," Wallenius CEO Lasse Kristoffersen said following the company's quarterly results.

While carmakers raced earlier this year to ship cars to the U.S. ahead of the tariff hike to 27.5%, the opposite happened at the start of the second quarter, Kristoffersen said.

"We saw that they held more back in the start of the second quarter but that volumes increased throughout the quarter," he said.