China’s COSCO Shipping Ports has said it will delay completing the acquisition of a stake in a container terminal in Germany’s largest port to the end of the year.

COSCO’s terminal arm moved last year to take a 35% stake in the operator of the container terminal in Tollerort in the port of Hamburg, which would mark the first time ever that a foreign firm has been able to invest in this famous port.

Tollerort is one of three container terminals belonging to Hamburger Hafen und Lagerhausgesellschaft (HHLA), a company in which the local Hamburg government has a majority stake. HHLA and Hamburg’s mayor have approved the deal.

However, last month the Federal Ministry of Economics and Technology started to voice concerns about COSCO’s entrance. Berlin must approve the deal, and now an investment review procedure based on the Foreign Trade Act is under way. Economy Minister Robert Habeck said in an interview with Reuters last week that he was leaning towards not allowing the deal, which would give China a stake in German critical infrastructure.

A rejection by Berlin would be “a one-sided, competition-distorting disadvantage for Hamburg compared to Rotterdam and Antwerp, where Cosco already owns terminal shares,” warned Hamburg’s mayor Peter Tschentscher, interviewed by Reuters.

Germany would put its port of Hamburg at a competitive disadvantage if it quashed a bid from China’s Cosco to buy a stake in a container operator, the port city’s mayor said.

“In order to keep up with international competition, it must also be possible for shipping companies to participate in terminals in Hamburg if this makes business sense,” Tschentscher added.

COSCO is already well entrenched in the city, operating its intra-European brand, Diamond Line, from there.