TOKYO (REUTERS) - Japanese wireless carrier SoftBank Corp on Tuesday (Dec 22) said it will lower its mobile fees, joining bigger rival NTT Docomo following government calls to cut prices to spur consumer spending elsewhere in the economy.

Japan's third-biggest mobile phone network operator by subscribers said lower price plans include charging 2,980 yen (US$29) for 20 gigabytes of data per month from March.

The plan will be offered online only and use "SoftBank on Line" branding. Line is merging with SoftBank's Internet business Z Holdings.

SoftBank also said it will cut fees at its main brand, launching a 6,580 yen plan with unlimited data, in contrast to its 8,480 yen 50GB plan currently.

The announcement, which follows pressure from Prime Minister Yoshihide Suga to reduce fees, marks a shift from offering low-price plans on its budget Ymobile brand while pushing consumers seeking the latest phones or more data onto expensive tariffs.

SoftBank Group Corp has slashed its shareholding to 40 per cent of the wireless carrier and investors are fearful of the price competition's impact on the telco's operating margin, which was 19 per cent in the year ended March.

SoftBank Corp's shares are languishing below the 1,500 yen price achieved in its blockbuster December 2018 initial public offering, in contrast to shares in SoftBank Group whose shares are trading near two-decade highs.