SINGAPORE -- The venture capital arm of Singapore's state-backed investment group Temasek Holdings, together with Japanese investors, will launch a $770 million fund that seeks to nurture tech startups into multibillion-dollar companies. Japanese investors will contribute 20% of the capital for the fund created by Vertex Ventures. As of Friday, investment house Risa Partners had committed $50 million, while Aozora Bank had pledged $20 million. Several more Japanese institutional investors are expected to take part by a September deadline. The fund is described as the first Vertex vehicle in which foreign investors play a major role.