Shanghai, June 30 (Reuters) - China stocks ended higher on Wednesday, with major tech indexes booking their biggest quarterly gains in a year on policy support from Beijing and strong earnings expectations. ** The blue-chip CSI300 index rose 0.7% to 5,224.04, while the Shanghai Composite Index firmed 0.5% to 3,591.20, also aided by soft factory activity data that soothed fears of policy tightening. ** Shenzhen’s start-up board ChiNext climbed 2.1% to a six-year high, while Shanghai’s tech-focused STAR50 index rose 1.7%. ** For the quarter, the CSI300 gained 3.5% and the SSEC climbed 4.3%. ** ChiNext jumped 26% for the quarter, while STAR50 advanced 27%, both posting their best quarterly gains in a year. ** Shares in China’s semiconductor firms jumped on expectations of robust earnings growth in the first half as a shortage of semiconductors pushed prices higher. ** Shenzhen Fine Made Electronics Group Co Ltd, Kingsemi Co Ltd, Sino Wealth Electronic Ltd and SG Micro Corp rose between 11% and 20%. ** The CSI all-share semiconductors & semiconductor equipment index climbed 4.8%. ** Analysts attributed the tech strength to Beijing’s policy support amid Sino-U.S. tech competition and rosy earnings growth in the first half. ** Semiconductors, as a new type of strategic resource, are pivotal to China’s economic development in coming decades, BOC International (China) said in a report, noting price hikes in the semiconductor sector. ** Growth in China’s June factory activity dipped to a four-month low on higher raw material costs, a shortage of semiconductors and a COVID-19 outbreak in the major export province of Guangdong, amid wider supply chain disruptions in Asia. ** China’s economic growth could be weak in the second half, indicating a neutral monetary policy with a loosening bias would continue, Essence Securities said in a report, adding weak growth could substantially decrease chances of monetary tightening. (Reporting by Shanghai Newsroom; Editing by Aditya Soni) Our Standards: The Thomson Reuters Trust Principles.