PSA Sines, the concessionaire for the Sines Container Terminal (Terminal XXI), launched the tender for the expansion of this port infrastructure. This expansion phase includes the construction of another 204 meters of quay in order to provide the terminal with a 1,150 meters long quay by the end of 2021, representing an investment of 16.5 million euros. This is the first expansion phase after the renegotiation of the Terminal XXI concession, which, in its final configuration, will offer a 1,750 meters quay, to be built by stages.

Terminal XXI is a part of the main international maritime routes in which the largest container ships in the world in operation are located, and this investment reinforces the terminal's capacity to receive several megacarriers simultaneously and thus increase its operational offer.

In October 2019 the Ports of Sines and the Algarve Authority (APS) and PSA Sines signed an amendment to the concession contract that allows new investments to be made regarding the expansion of the quay and the resizing and modernization of the terminal, projecting an increase in the annual handling capacity from 2.3 to 4.1 million TEU (20-foot containers).