Irvine-based eye drug maker Ista Pharmaceuticals Inc. said it has rejected a buy-out offer of $314 million from Valeant Pharmaceuticals International Inc. in Ontario, Canada.

The bid came to $6.50 a share, a premium of about 67%.

Ista called the offer "grossly inadequate," according to Dow Jones Newswires.

Ista President and Chief Executive Vicente Anido said the bid wasn’t in shareholders' best interest. He said the company expects "significant revenue growth in 2012 and beyond."

Valeant has roots in Orange County. One of its predecessor companies was Costa Mesa-based ICN Pharmaceuticals Inc. ICN later changed its name to Valeant and moved its headquarters to Aliso Viejo.

Biovail Corp. bought Valeant in 2010, moved its operations to Canada, and adopted the name.

Valeant publicized its offer after Ista rejected the bid in private.

Valeant has grown to a market value of about $13 billion in recent years. It has steadily acquired and marketed older drugs for conditions that get less attention from Big Pharma.

Valeant appears ready to pursue a deal further. Chairman and Chief Executive J. Michael Pearson said the company would consider upping its offer if it’s allowed to conduct due diligence on Ista, according to reports.