While the P.108B's troubled development continued, Piaggio's workload was further stressed by the request for new transport aircraft, capable of long-range flights to South America for "Linee Aeree Transcontinentali Italiane" (LATI). The intention in 1939 to license-build the Boeing 307 Stratoliner wasn't realised, so in 1940, it was proposed to use the P.108C as an "interim" transport, awaiting the P.126C and even the P.127C six-engined variant. They were planned to have a pressurised cabin to accommodate 32 passengers in a wider fuselage, but no armament. The prototype first flew on 16 July 1942, when there were no longer any transatlantic lines to serve. Despite this, and the inability of Piaggio to deliver P.108B bombers on time, an order for a further five P.108Cs was placed.