By Andy Bruce, William Schomberg and David Milliken LONDON (Reuters) – British finance minister Kwasi Kwarteng, who last month sparked a bond market rout and international consternation with unfunded tax cuts, brought forward his next budget announcement by nearly a month and named a Treasury insider to run the department. Under pressure to rebuild investor confidence in the new government’s economic agenda, Kwarteng said he would reveal longer-term tax and spending plans and independent economic forecasts on Oct. 31, not Nov. 23 as previously scheduled. He also announced on Monday that experi…