Fuel supply system with transfer pump and fuel supply method

A system and method for supplying fuel to an internal combustion engine is disclosed including a fuel tank (11) having a first fuel sump portion (11a), in which a fuel pump (12) is disposed, and a second fuel sump portion (11b) formed separate from the first fuel sump portion (11a). A transfer pump (17) which supplies fuel from the second fuel sump portion (11b) to the first fuel sump portion (11a) is driven with traveling energy of divergent fuel forming a portion of fuel to be supplied to the internal combustion engine from the fuel pump (12). A divergent fuel control unit (20) is disposed in a supply line of the diverged fuel to decrease the flow rate of the divergent fuel in dependence on an increase in a demanded fuel flow rate of the internal combustion engine, thereby minimizing a compensation flow rate of the fuel pump (12) as a whole and the flow rate size thereof.