TOKYO, Aug 31 (Reuters) - Shares in wireless carrier SoftBank Corp fell 3% on Monday after parent SoftBank Group Corp said it would sell up to 22% of the telco's shares, which could slash its holding in the carrier to 40%.

SoftBank Group's shares were up almost 5% as a series of massive asset sales and share buybacks fuel its climb from March lows.

SoftBank Corp's shares were trading at 1,385 yen in Monday morning trade - below its December 2018 IPO price of 1,500 yen, as its CEO Ken Miyauchi struggles to excite investors about the long-term growth prospects for Japan's third-biggest carrier.

SoftBank Group "is manifesting a very disciplined approach to managing its balance sheet (in a welcome change) but does not bode so well for (SoftBank Corp's) shareholders," Jefferies analyst Atul Goyal wrote in a note.

Group CEO Masayoshi Son has already cut exposure to the telco he built despite its ample dividends as he bulks up cash reserves during the coronavirus outbreak. (Reporting by Sam Nussey; Editing by Himani Sarkar and Edwina Gibbs)