Complex sentence: Government-linked companies play a substantial role in Singapore's economy, which are owned through the sovereign wealth fund Temasek Holdings, which holds majority stakes in several of the nation's largest companies, such as Singapore Airlines, SingTel, ST Engineering and MediaCorp.
Split into simpler sentences: Government-linked companies play a substantial role in Singapore's economy. Sovereign wealth fund Temasek Holdings holds majority stakes in several of the nation's largest companies, such as Singapore Airlines, SingTel, ST Engineering and MediaCorp.