What is the ruling on buying shares in the "du" integrated telecommunications company?

It is impermissible to contribute to companies that engage in usury (lending or borrowing) or deposit their funds in usurious banks without a necessity for safekeeping, or companies that are involved in prohibited activities such as pornography websites, enabling forbidden channels, or gambling-based competitions. If a company is free from these prohibitions, then it is permissible to purchase its shares.