WASHINGTON, Apr 21 (Reuters) US President Donald Trump will sign today an executive order on finding and reducing tax burdens and two memoranda ordering reviews of financial corporate regulations, a White House official said. The memoranda ask the Treasury secretary to review the Orderly Liquidation Authority and the Financial Stability Oversight Council, both part of the Dodd-Frank law enacted under President Barack Obama's administration after the 2008-2009 financial meltdown. The executive order directs the Treasury secretary to review significant tax regulations issued in 2016 to determine if any of them impose an undue financial burden on American taxpayers, add undue complexity or exceed statutory authority, the statement said yesterday. REUTERS SDR 0559