Speculation about who may or may not finance Tesla Inc. CEO Elon Musk's audacious plan to take the carmaker private is distracting deal-makers from a normally quiet August spent in the Hamptons or southern France.

As the intrigue enters a second week, with pressure increasing on the billionaire founder to explain how a deal would be funded, one of the world's most active investors has already ruled itself out.

SoftBank Group Corp., the Japanese conglomerate that has been touted as a potential source of capital for a buyout of the carmaker, isn't planning to participate in such a deal, according to people with knowledge of the matter. The company, which held talks with Musk in 2017 about a possible investment, isn't interested in revisiting such a plan, said the people, who asked not to be identified as the details aren't public.