WASHINGTON, Sept 18 (Reuters) - The White House said on

Wednesday that the review process of Nippon Steel's ( NISTF ) proposed

purchase of U.S. Steel is ongoing and that it knows of no delay

or extension.

A source told Reuters this week that the U.S. national

security panel reviewing Nippon Steel's ( NISTF ) $14.9 billion bid for

U.S. Steel let the companies refile their application for

approval of the deal, delaying a decision on the politically

sensitive merger until after the Nov. 5 presidential election.