NEW YORK (Reuters) - TradeZero, a Bahamas-based online broker-dealer, said on Thursday it had launched the world's first "dark pool" exchange for bitcoin to enable institutional investors to execute large trades.<div><a href="http://feeds.reuters.com/~ff/reuters/technologyNews?a=o_CAHWWso-U:et2Y_kv91QA:yIl2AUoC8zA"><img src="http://feeds.feedburner.com/~ff/reuters/technologyNews?d=yIl2AUoC8zA" border="0" /></a> <a href="http://feeds.reuters.com/~ff/reuters/technologyNews?a=o_CAHWWso-U:et2Y_kv91QA:V_sGLiPBpWU"><img src="http://feeds.feedburner.com/~ff/reuters/technologyNews?i=o_CAHWWso-U:et2Y_kv91QA:V_sGLiPBpWU" border="0" /></a> <a href="http://feeds.reuters.com/~ff/reuters/technologyNews?a=o_CAHWWso-U:et2Y_kv91QA:-BTjWOF_DHI"><img src="http://feeds.feedburner.com/~ff/reuters/technologyNews?i=o_CAHWWso-U:et2Y_kv91QA:-BTjWOF_DHI" border="0" /></a></div><img src="http://feeds.feedburner.com/~r/reuters/technologyNews/~4/o_CAHWWso-U" height="1" width="1" alt="" />