The president and managing director of Shenzhen-based brokerage J&A Securities will cut his salary by 30 per cent for six months and has apologised to fellow staff after the firm was found to have violated trading rules. Company officials said Zhang Guoqing had decided to volunteer responsibility for the firm's regulatory breaches rather than wait for an order from the China Securities Regulatory Commission (CSRC). The brokerage was punished for helping Guangshen Railway speculate in mainland stocks with its listing proceeds. J&A Securities was barred from proprietary trading for six months and its illegal income has been confiscated. Officials would not say how much the army-backed brokerage's helmsman earned each month, but industry practitioners said Mr Zhang 'does not have to live on salary', indicating salary was not a good indicator to measure his income. As with other brokerages' senior executives, Mr Zhang's income includes salary, housing, allowances and bonuses. Analysts said Mr Zhang's high-profile attempt to lower his salary was a stance that indicated his acceptance of mainland authorities' recent clampdown on the overheated stock market. A letter of apology by Mr Zhang was issued to the 2,000-strong workforce early this week requesting that fellow employees comply with government rules. The letter also asked workers not to bad-mouth other firms being punished with the brokerage. The apology - albeit an internal one - came two days after Shenzhen Development Bank issued its first public apology to its shareholders for its involvement in one of China's biggest market manipulation scandals. The Shenzhen-listed bank, China's only banking counter, has promised to draft measures to discipline and improve management. Beijing's systematic and sustained clampdown was essentially wrapped up on June 12 when financial and securities regulators acknowledged for the first time that four brokerages, two banks, a Hong Kong-listed company and their senior executives had been punished for serious trading violations. It is understood that J&A Securities has informed its major shareholders and clients of the punishment. It also has been ordered by the CSRC to shut a Hong Kong subsidiary, J&A Financial Services, which helped Guangshen Railway use its proceeds from the H-share company's listing to play the markets. Analysts have said barring J&A from proprietary trading - even for half a year - would crimp its earnings as the high-risk business had long been the brokerage's major income source.