By Scott Murdoch and Makiko Yamazaki SYDNEY/TOKYO (Reuters) -Hong Kong-based activist fund Oasis Management has voted in favour of a shareholder proposal demanding Toshiba Corp solicit buyout offers from private equity firms, a source with direct knowledge of the matter told Reuters on Wednesday. Oasis also voted against the Japanese industrial conglomerate's plan to break itself up, said the source, who was not authorised to speak to media and declined to be identified.