Short answers, pulled from the story.
The London Six-Power Conference aimed to pave the way for Germany's participation in the international community by creating a democratic and federal government in the American, British, and French occupation zones. The six participating nations were the United States, Britain, France, and the three Benelux countries.
The conference was held in two sessions in 1948. The first session ran from the 23rd of February to the 6th of March, and the second session ran from the 20th of April to the 2nd of June.
The Soviet Union was excluded because the four-power Foreign Secretary Conference of the 15th of December 1947 had ended without agreement on the German question. The Communist takeover of Czechoslovakia in early 1948 made the western allies unwilling to wait further for Soviet cooperation.
The Frankfurt Documents were the recommendations delivered by the three western military governors to the German Minister Presidents, setting out how the new West German state should be established. They took their name from Frankfurt, the city where the military governors met with the Minister Presidents to hand over the directives.
France agreed to the merger of the three western occupation zones on condition that the Saarland be financially integrated with France and that the Ruhr area be placed under international control. Both conditions reflected French concern about German industrial power.
The Soviet Union ended its participation in the Allied Control Council as a direct consequence of the London Conference. This formally broke up the four-power body that had governed postwar Germany, deepening the division between the western and Soviet zones.