BRUSSELS—The European Union launched a legal challenge against China at the World Trade Organization on Friday, arguing that Chinese courts were preventing European companies from protecting their telecom technology patents. The European Commission, which filed the challenge on behalf of the EU’s 27 members, said EU companies were being deterred from going to a foreign court to safeguard their standard-essential patents (SEPs). The Commission has also consulted the United States and Japan, whose standard-essential patent holders face similar challenges and which want to be setting global tech standards, rather than leaving this to Beijing. Mobile phone manufacturers need to obtain licenses for SEPs for their products to meet certain international standards. The Commission said Chinese courts had, since August 2020, been issuing “anti-suit injunctions,” which prohibit EU companies from going to foreign courts, with the threat of heavy fines as a deterrent. In one case, the fine was 130,000 euros …