(REUTERS) - A blow for those with hopes of legal pot shops opening in Berlin.

The German Federal Institute for Drugs and Medical Devices rejected the application of a Berlin district to legally control the sale of hash and marijuana.

The district's proposal was to open four shops where adults registered in the borough could buy up to 10g of pot at a time - and no more than 60g per month.

The district's mayor Monika Hermann said: "It was never our goal - as I have said many times before - to establish a 'happy pothead zone'... But our goal was to act in the interest of youth protection and consumer protection, and to implement the intention of legislation."

The district has one month to decide whether it will file a petition to overturn the decision.