LOS ANGELES (MarketWatch) -- The White House is expected to nominate Federal Reserve Vice Chairwoman Janet Yellen as the chairwoman of the Federal Reserve, according to a Wall Street Journal report late Tuesday. An announcement is likely to be made as soon as Wednesday. Yellen has served as vice chair of the central bank since 2010, and would succeed current Fed Chairman Ben Bernanke. Bernanke's second term as Fed chief will end on Jan. 31, 2014.