VTX Holdings (ASX:VTX) has been granted a trading halt by the ASX, with its shares placed in pre-open.VTX requested the halt pending the due diligence results of the proposed acquisition of NexGen Networks Limited.NexGen has developed a 'virtual' software technology, "NGN" - which is says optimises, rebuilds and intelligently compresses data.There is significant global market opportunity estimated at $100 billion globally.The halt will remain in place until the opening of trade on Wednesday 15th July 2015, or earlier if an announcement is made to the market. Proactive Investors Australia is the market leader in producing news, articles and research reports on ASX emerging companies with distribution in Australia, UK, North America and Hong Kong / China.