Bengang Steel Plates Co has fallen victim to the downturn which has hit the mainland share market since May, becoming the first B-share company this year to fall below its issue price on its trading debut. The Shenzhen B share plunged as much as 20 per cent in the first 30 minutes of trade yesterday, but regained most of its early losses in late trading to end 1.26 per cent lower at $2.35 against a 5 per cent fall in Shenzhen's B-share index. Its issue price was $2.38. About 104.3 million Bengang shares traded yesterday - about a quarter of the total of 400 million B shares it offered to foreign investors last month, to raise $952 million. A Hong Kong-based dealer said the mainland B-share market was clouded by a string of market-dampening moves restricting mainlander involvement in the B-share market and rumours of Beijing's further crackdown on the domestic A-share market. Mainland securities regulators have ordered brokers to stop buying shares for domestic clients with illegal B-share accounts from July 14. Shareholders of illegal accounts could sell down their holdings but were banned from buying new shares.