WASHINGTON (Reuters) - The U.S. Federal Reserve said on Friday it had approved the acquisition of the U.S. operations of Spanish lender BBVA by PNC Financial Services Group Inc, clearing the way for a deal first announced in November. The $11.6 billion cash acquisition will be the second largest since the 2008 financial crisis when completed, creating a bank with nearly $650 billion in assets spread across roughly two dozen U.S. states. Reporting by Pete Schroeder; Editing by Leslie Adler Our Standards: The Thomson Reuters Trust Principles.