The signature of former OMB Director Lew is pictured in presidential memorandum

The signature of former Office of Management and Budget (OMB) Director Jacob "Jack" Lew is pictured in this presidential memorandum obtained on January 10, 2013. U.S. President Barack Obama joked on Thursday that he considered taking back his offer to make Lew, currently the president's White House Chief of Staff, his next Treasury secretary after seeing - thanks to media reports - his loopy, illegible signature. REUTERS/OMB/Handout (UNITED STATES - Tags: POLITICS BUSINESS SOCIETY) ATTENTION EDITORS - THIS IMAGE WAS PROVIDED BY A THIRD PARTY. FOR EDITORIAL USE ONLY. NOT FOR SALE FOR MARKETING OR ADVERTISING CAMPAIGNS. THIS PICTURE IS DISTRIBUTED EXACTLY AS RECEIVED BY REUTERS, AS A SERVICE TO CLIENTS