Yellen says economy on track, defends Fed 'transparency'

By Howard Schneider and Michael Flaherty WASHINGTON (Reuters) - Federal Reserve Chair Janet Yellen said on Wednesday the U.S. central bank remains on track to raise interest rates this year, with labor markets expected to steadily improve and turmoil abroad unlikely to throw the U.S. economy off track. "If the economy evolves as we expect, economic conditions likely would make it appropriate at some point this year to raise the federal funds rate," Yellen said in testimony prepared for