A US fibre optics maker has been forced to abandon a planned joint venture with China’s Tangshan Caofeidian Investment Corporation (TCIC) after the White House blocked the transaction on concerns that it would threaten national security, the Financial Times reported. Emcore (NASDAQ.EMKR), a New Mexico-based components maker for fibre optics and solar panels, said it withdrew a voluntary filing with the Committee on Foreign Investment after the executive branch panel raised "regulatory concerns" about the venture. Emcore had planned to sell 60% of its fibre optics business to TCIC for US$27.8 million under the terms of the deal. This is the second time in less than a year that the Obama adminstration has sought to block a tie-up involving a Chinese company because of security concerns. Washington also forced another Chinese company to scrap a bid late last year to buy a 51% stake in the Nevada mining group, Firstgold (TSX.FGD, OTCBB.FGOC).