Nov 19 (Reuters) - Treasury Secretary Steven Mnuchin on Thursday asked the Federal Reserve to return more than $400 billion in unused funds from the massive March pandemic relief package so that Congress can reappropriate it to deliver economic stimulus. “I am requesting that the Federal Reserve return the unused funds to the Treasury,” Mnuchin said in a letter to Fed Chair Jerome Powell. “This will allow Congress to re-appropriate $455 billion, consisting of $429 billion in excess Treasury funds for the Federal Reserve facilities and $26 billion in unused Treasury direct loan funds.”