Frederick V King of Denmark was obligated by treaty to send troops to defend the Duchies of Bremen and Verden, both ruled in personal union with Britain and Hanover, if they were threatened by a foreign power. As he was eager to preserve his country's neutrality, he attempted to broker an agreement between the two commanders. Richelieu, not believing his army was in any condition to attack Klosterzeven, was receptive to the proposal as was Cumberland who was not optimistic about his own prospects.

On 10 September at Klosterzeven the British and French signed the Convention of Klosterzeven which secured the immediate end of hostilities and led to Hanover's withdrawal from the war and partial occupation by French forces.

The agreement was deeply unpopular with Hanover's ally Prussia, whose western frontier was severely weakened by the agreement. After the Prussian victory at Rossbach on 5 November 1757, King George II was encouraged to disavow the treaty. Under pressure from Frederick the Great and William Pitt, the convention was subsequently revoked and Hanover re-entered the war the following year. The Duke of Cumberland was replaced as commander by Duke Ferdinand of Brunswick.