HONG KONG (REUTERS)- China's securities regulators punished 19 institutional investors as the authorities tighten scrutiny over price-setting behaviours under a more liberalised listing system. China launched the tech-focused Star Market in Shanghai along with the introduction of a US-style, registration-based initial public offering (IPO) system in that market in mid-2019. The Securities Association of China (SAC) said late on Friday that a joint probe with the Shanghai Stock Exchange over Star IPOs had exposed issues with 19 institutional investors. The problems included weak internal controls, inadequate rationale for price-settings, non-compliance with stipulated procedures and improper storage of working papers, the…