** Shares of U.S. homebuilders fall in afternoon trade
** President Donald Trump's administration is exploring the possibility of opening an antitrust investigation into U.S. homebuilders in an effort to tackle the country's housing affordability crisis, Bloomberg News reports
** Report says officials have grown concerned that industry trade group called Leading Builders of America could be used to restrict housing supply or coordinate pricing, citing people familiar with the matter
** D.R. Horton down 2.8%, Lennar LEN.N down 2%
** Peer Pultegroup PHM.N, KB Home KBH.N, and NVR Inc NVR.N also down between 1% and 2%
** PHLX Housing Index .HGX up 10% YTD
(Reporting by Anshuman Tripathy)
((Anshuman.Tripathy@thomsonreuters.com))