Japanese manufacturing giants Hitachi and Mitsubishi Heavy Industries denied Thursday they are in talks to combine their businesses. Both companies reiterated that media reports about a possible business combination were untrue, just hours after Hitachi President Hiroaki Nakanishi told a throng of reporters that the news would be released later. The Nikkei financial daily first reported that Hitachi and Mitsubishi Heavy had agreed to start negotiations for a deal that would create one of the world\'s biggest infrastructure companies. In a terse statement, Hitachi said the article \"is not based on fact.\" Mitsubishi Heavy said separately that it had not entered talks with Hitachi and had \"no plans to agree\" to such negotiations. Article continues below Hopeful investors Nonetheless, the news made waves among hopeful investors. Hitachi shares finished up 1.7 per cent, while Mitsubishi Heavy jumped 3.4 per cent. Hitachi is a 100-year-old multinational conglomerate with 360,000 employees, hundreds of subsidiaries and more than $100 billion in annual revenue. Its business spans a vast array of products and services, from rice cookers to elevators to nuclear power plants. It is banking its future on a global expansion of its \"social innovation\" business — a broad category that spans the various elements of city infrastructure. Demand for urban infrastructure is growing worldwide, from power plants to data centres to proposed high speed rail projects in the US and Asia. Mitsubishi Heavy is Japan\'s largest heavy machinery maker with $36 billion in annual revenue.