Sanofi-Aventis was formed in 2004, when Sanofi-Synthélabo acquired Aventis. In early 2004, Sanofi-Synthélabo made a hostile takeover bid worth €47.8 billion for Aventis. Initially, Aventis rejected the bid because it felt that the bid offered inferior value based on the company's share value, and the board of Aventis went so far as to enact poison pill provisions and to invite Novartis to enter merger negotiations. The three-month takeover battle concluded when Sanofi-Synthélabo launched a friendly bid of €54.5 billion in place of the previously rejected hostile bid. The French government played a strong role, desiring what it called a "local solution", by putting heavy pressure on Sanofi-Synthélabo to raise its bid for Aventis and for Aventis to accept the offer and by rejecting Aventis' poison pill proposal. One of the largest risks in the deal for both sides, was the fate of the patents protecting Clopidogrel (Plavix) which was one of the top-selling drugs in the world at the time and the major source of Sanofi's revenue.