Hedge fund ValueAct Capital said on Thursday it would return to the board of directors of Valeant Pharmaceuticals International Inc, which is pursuing a hostile takeover offer for Allergan Inc, and that it planned to increase its stake in the company. ValueAct Chief Executive Officer Jeffrey Ubben said in a statement that once he is on the board, he would work with Valeant on its $53 billion acquisition of Allergan, a deal whose certainty he has previously questioned.