Mylan has today rejected Teva Pharmaceutical Industries' unsolicited $40 billion takeover offer, but left the door open for talks. 

"Our board will certainly not consider engaging in discussions to sell the company unless the starting point of the discussions is significantly in excess of $100 per share," Mylan said. 

Teva, the world's biggest maker of generic drugs, has offered $82 per share in cash and stock for Mylan. 

However, Mylan said a combination with Teva would expose it to a "problematic culture and leadership with poor record of delivering shareholder value."

Mylan also said it remained committed to its offer for Perrigo. 

Last week, Mylan said it would take its $31 billion offer for Perrigo directly to shareholders, in what is set to be one of the most high-profile hostile takeover attempts of the year. 

Mylan's pursuit of Perrigo, a major producer of over-the-counter drugs, is widely seen as an attempt to fend off Teva.