Four people, including the former chairman of publicly listed Semtech International Holdings, have been charged for alleged corruption in relation to share placement of the company, and research reports of it and another listed company.

The defendants are former Semtech chairman Derek Wong, 37, former American Express Bank senior director Earnest Leung, 48, VC Brokerage divisional managing director Yung Ka-tim, 48, and merchant Ko Kin-hang, 37.

They were arrested by the Independent Commission Against Corruption in July. They face nine charges and will appear at Eastern Magistracy on March 24.

One of the charges alleges Wong offered $170,000 to Yung for showing or having shown favour to him in relation to affairs or business relating to Semtech shares. Wong is also alleged to have offered $400,000 to Leung for the same reason. Yung and Leung each face a count of accepting $170,000 and $400,000 from Wong for the same reason.

Ko faces five charges - three of which allege he offered $60,000 to a research manager of a securities company for writing research reports on Semtech and Peace Mark (Holdings).

The remaining two charges allege Ko offered $20,000 and a mobile phone to an associate director of a financial services company for the same reason.