April 15 (Reuters) - A federal judge on Tuesday rejected a request by Standard & Poor's to split up the U.S. government's $5 billion lawsuit accusing it of lying about its credit ratings, paving the way for a single trial in the civil fraud case.
U.S. District Judge David Carter in Santa Ana, California said the central question, whether S&P schemed to defraud, "will be answered by facts that are common to all, or nearly all, of the securities" underlying the case.
S&P, a unit of McGraw Hill Financial Inc, was accused of causing losses for federally insured banks and credit unions by inflating ratings to win more fees from issuers, and being too slow to downgrade debt backed by souring mortgages, contributing to the 2008 financial crisis.
The credit rating agency had proposed holding a trial in two parts, with the first focusing on just 17 of the roughly 160 securities at issue, where Citigroup Inc was alleged to have suffered losses.
(Reporting by Jonathan Stempel in New York; Editing by Steve Orlofsky)