Chennai-based industrialist C. Sivasankaran has acquired a 51 per cent stake in S Tel for about Rs 11.5 billion. The deal has been carried out by Sivasankaran's investment arm Sterling Infotech Group. The move comes four years after Sivasankaran sold his stake in Aircel to Malaysia's Maxis Communications for $1.08 billion. He was then barred from buying more than a 10 per cent stake in any Indian telecom company for three years, as part of a noncompete clause he had signed with Maxis. Skycity Foundations and Telecom Investments, the two promoters of S Tel, had earlier sold a 49 per cent stake in S Tel to Bahrain Telecom.