 Hostilities ceased in March 1940 with the signing of the Moscow Peace Treaty . Finland ceded territory representing 11 % of its land area and 30 % of its economy to the Soviet Union . Soviet losses were heavy , and the country 's international reputation suffered . While the Soviet Union did not conquer all Finland , Soviet gains exceeded their pre @-@ war demands . They gained substantial territory along Lake Ladoga , providing a buffer for Leningrad , and territory in northern Finland . Finland retained its sovereignty and enhanced its international reputation . 
