Foreign ownership of Celltrion Inc., a South Korean biotech company, has risen over the past six years, driven by strong earnings and increased relationship-building activities with overseas investors, the company said Tuesday. Offshore ownership of the firm rose 3.4 percentage points to 24.5 percent over the past six months as of end-June, according to data provided by the company. During the same period, foreign investors purchased around 1.8 trillion won ($1.18 billion) in bio companies liste