WASHINGTON, Jan 10 (Reuters) - The Republican-led U.S. House of Representatives Financial Services Committee on Wednesday sent a letter to the Securities and Exchange Commission, demanding a briefing on a fake post on the SEC's X social media account from a day earlier.

The U.S. securities regulator said someone briefly accessed its X, formerly called Twitter, account on Tuesday and posted a fake message saying it had approved exchange traded funds (ETF) for bitcoin, a move eagerly awaited by the crypto industry.

The SEC eventually on Wednesday approved the first U.S.-listed ETFs to track bitcoin.

(Reporting by Kanishka Singh in Washington Editing by Chris Reese)