(Reuters) - Valeant Pharmaceuticals International Inc VRX.TO said on Tuesday it will "improve" its $47 billion takeover offer for drugmaker Allergan Inc AGN.N, a day after the U.S. company rejected the bid.
Allergan shares rose 2 percent to $162.75 in pre-market trading.
Canada's Valeant said it would make the change to its cash and stock offer at a May 28 webcast in which it will discuss details of its plans for Allergan's business. Valeant said it remained committed to getting the deal done but would remain "financially disciplined."
Allergan, which makes the popular anti-wrinkle treatment Botox, said on Monday that Valeant's business model was unsustainable and the offer was too risky because of uncertainty about the company's long-term growth.
Valeant, fresh off its purchase of Bausch & Lomb Inc last year, and investor William Ackman of Pershing Square Capital Management made an offer for Allergan on April 22. Allergan put in a so-called "poison pill" within days to slow Ackman from increasing his nearly 10 percent stake in Allergan.
Valeant said at that time it planned to cut costs at Allergan by about $2.7 billion, including in research and development.
"We will not stop our pursuit of this combination until we hear directly from Allergan shareholders that you prefer Allergan's "stay the course plan" to a combination with Valeant," Valeant CEO, J. Michael Pearson said on Tuesday in a letter to shareholders.
(Reporting by Esha Dey in Bangalore; Editing by Saumyadeb Chakrabarty)