Allergan Inc., the maker of the Botox wrinkle treatment, rejected an increased bid of about $54 billion from Valeant Pharmaceuticals International Inc. and investor Bill Ackman, calling it undervalued.

Allergan, based in Irvine, California, said in a statement that it turned down the offer of $72 a share in cash and 0.83 a share of Valeant stock. On May 28, Laval, Quebec-based Valeant raised its bid for the first time to $49.4 billion from $45.7 billion.

“Valeant’s revised proposal substantially undervalues Allergan,” Allergan Chief Executive Officer David Pyott said in a statement today. “We do not believe Valeant’s proposal reflects Allergan’s growth prospects, nor does it offer sufficient or certain value to warrant discussions between Allergan and Valeant.”

Allergan shares fell 1.7 percent to $161.35 at 8:37 a.m. during early trading in New York.

Pershing Square Capital Management LP, Bill Ackman’s hedge fund, is using its own 9.7 percent ownership to push the sale. It has filed to start the process for a special shareholder meeting to remove most of Allergan’s board to get the deal done.

If Allergan’s management and board of directors choose not to discuss the deal, “a new board, appointed by shareholders, will negotiate a transaction,” Ackman said in a June 2 conference call with investors. Pershing Square agreed to forego the cash portion of the bid to boost the incentive for other shareholders.

The Allergan deal would be Valeant’s largest, as part of Valeant Chief Executive Officer Michael Pearson’s goal of joining the ranks of the world’s five biggest drugmakers by the end of 2016. The deal would eclipse the $8.7 billion purchase of Bausch & Lomb Inc. last year.

“We will be patient, we will get this deal done,” Pearson said on the June 2 conference call. “We believe that speed in concluding a transaction is in the best interest of both shareholders.”