Rakuten Mobile Inc. rolled out its ultrahigh speed 5G mobile internet service Wednesday at less than half the price offered by Japan's three mega-carriers.

The company, which only debuted as the fourth mobile communications operator in April, is still far behind the three mobile giants — NTT Docomo Inc., KDDI Corp. and SoftBank Corp.

But the bold price plan could give Rakuten a competitive edge and fuel the momentum toward cheaper phone fees amid pressure from Prime Minister Yoshihide Suga to slash service charges.