SoftBank Group Corp. founder Masayoshi Son said he is considering a new type of fund for startup investing, showing his determination to keep cutting deals after missteps with WeWork and several other companies.

The Japanese billionaire unveiled his $100 billion Vision Fund three years ago and had been planning on raising a similarly sized second Vision Fund. But as he discussed earnings in Tokyo Wednesday, he conceded that raising money from limited partners for the second fund has been difficult and he may instead make startup investments solely with SoftBank's capital for a year or two.

"A lot of our planned investors have been worried by the trouble at WeWork and Uber and we heard their feedback," Son said. "So before we officially launch SoftBank Vision Fund 2, maybe we start from a smaller scale and start from a shorter period in terms of investment as sort of a bridge."