Leaders in the mainland's battered manufacturing heartland of Guangdong have unveiled 150 key industrial and infrastructure projects in an unprecedented package to help ignite economic activity in the province. But economists doubted whether all the projects listed in the package - the combined value of which was not given - were feasible or economically efficient. The stimulus package included the construction of 19 experimental zones for economic reforms and streamlined administration, 42 key domestic or international industrial bases, 11 new industrial zones and 63 large infrastructure projects, mainland media reported yesterday. Five of the 11 new industrial zones would involve cross-border co-operation between the delta and either Hong Kong or Macau. The construction programme was part of a 12-year development blueprint that Beijing outlined last month to boost economic co-operation and interaction among the three regions. Authorities said the blueprint would enable the Pearl River Delta to become globally competitive and the most vigorous area in the Asia-Pacific region by 2020. It aimed to make hi-tech industries, services, finance, automobile manufacturing, steel, petroleum and chemicals the major sources of the delta's development. Guangdong Communist Party secretary Wang Yang described the stimulus package as a clear and strong signal that the delta was changing from a labour-intensive and export-driven manufacturing hub. 'We can't draw new investors without a strong stimulus package and new policies,' Mr Wang told a three-day working conference on the blueprint, the Southern Metropolis News reported. Most of the infrastructure projects detailed in the package are highways, railways, bridges, airports, power plants and water-control projects. Neither Mr Wang nor the blueprint presented any substantial steps to transform the delta into an upgraded industrial hub. Guangdong economists doubted authorities could achieve the many industrial goals in the plan. They suggested the dozens of infrastructure projects could be just another spending spree to blindly spur gross domestic product. Analysts also said the unprecedented scale of the planned stimulus package indicated the province was confronting its hardest times in decades. Shenzhen-based economist Jin Xinyi said Guangdong had never been given such a huge economic stimulus package by the central government. 'Also, Beijing has never before outlined such a blueprint for the province to bolster its development and cross-border co-operation,' he said. 'It will be an unprecedented opportunity for Guangdong.' Economists urged officials to sensibly plan infrastructure projects and prevent corruption.