The operator will pick up nine million new subscribers in the latest in a string of acquisitions across Eastern Europe, India and South Africa.
But the news comes shortly after falling profit margins depressed the company's share price by 11 per cent.
Vodafone claimed that the Telsim deal represents an opportunity in a fast-growing market despite suggestions that it has paid highly for the privilege.
The firm also faces a huge uphill climb to catch the number one Turkish operator, Turkcell, which has 25.6 million subscribers.
Vodafone faced stiff competition from operators in Kuwait, Egypt and Dubai in the battle to acquire Telsim. The operator is expected to invest about $1bn in Telsim over the next three years to improve services.
Vodafone chief executive Arun Sarin said: "With a larger population than every European country except Germany, and a penetration level of approximately 53 per cent, the Turkish market represents a major growth opportunity."
The move follows Vodafone's $3.5bn investment in telecoms companies in Romania and the Czech Republic, the £840m spent on acquiring 10 per cent of Bharti in India in October, and the £1.3bn investment in increasing its stake in Vodacom in South Africa last month.
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