Paul Bisaro, Actavis plc’s acquisition-hungry chief executive officer, and Brent Saunders (pictured) of Forest Laboratories Inc. met for the first time in January at the JPMorgan health-care conference in San Francisco.

The reason was “just to say hi,” Bisaro recalled.

Now, a month later, that meeting has blossomed into a $25 billion deal that will help Bisaro cap a plan he’s had in the works for four years. The goal: Turning a mid-size generic- drug maker into a diversified, global pharmaceutical company with higher-margin injectable medicines and brand-name products added to the company’s collection of copycat drugs.

“Forest presented an extraordinarily unique opportunity to create a new kind of company,” Bisaro, 53, said after his Dublin-based company announced yesterday it was buying Forest, the New York-based maker of the Alzheimer’s drug Namenda and the blood-pressure pill Bystolic.

While Actavis had long considered Forest an acquisition target, it wasn’t until Saunders stepped in as Forest CEO with the backing of billionaire investor Carl Icahn that such a deal became possible.

Saunders’s predecessor, Howard Solomon, headed the company for more than three decades, and had said he possibly planned to install his son as successor. As a result, “we understood any type of transaction wasn’t going to be doable,” Bisaro said in a telephone interview.

That’s where Icahn came in.

Icahn’s Push

Icahn is the second-biggest Forest investor with 11.3 percent of the company, according to data compiled by Bloomberg. Icahn had fought for five years with Solomon over the direction of the company, winning one board seat in 2012 and a second in 2013.

In September, the board finally bent to Icahn’s wishes and replaced Solomon with Saunders, a former CEO at Bausch & Lomb Inc., opening the way for Bisaro to take advantage of their San Francisco meeting to test the waters anew.

“I hadn’t really spoken to Brent” before that, Bisaro said in a telephone interview. “I didn’t know him well.”

Over the next five weeks, though, the two men became familiar discussing what a combined company would look like, Bisaro said. The result was a deal for Forest that was three times bigger than any Bisaro had ever done at Actavis, a company that has completed $14.6 billion in purchases with six deals over three years. Successful completion of the Forest acquisition will change Actavis’s mix of sales, provide the combined drugmaker with more than $1 billion in cost savings, and bring Forest’s brand-name products to more markets.

Long Sought

“We’ve been thinking about this process for four years,” Bisaro said. “How do we become a more balanced pharmaceutical company not just across North America, but the world?”

Actavis was formerly known as Watson Pharmaceuticals Inc. The company in 2012 acquired the Swiss-based generics company Actavis and took on the Actavis name.

Last year, the Actavis purchased Warner Chilcott Plc, a pharmaceutical company, for $9.2 billion including net debt in a deal that allowed it to expand in women’s health and urology. That purchase gave the company an Irish corporate domicile that lowered its tax rate to 17 percent from 37 percent.

With the Forest bid, “this is a company that’s trying to create balance between brands and generics,” Saunders in a conference call. “We believe, over time, that being able to offer customers a variety of products in both branded and generics will be something that will give us an advantage over many of our competitors.”

Rapid Rise

Actavis, run from Parsippany, New Jersey, has grown rapidly since Bisaro took over in 2007, when he was recruited from his job as chief operating officer for Barr Pharmaceuticals Inc. The year he started at Actavis, the company was worth about $2.8 billion, which wouldn’t even make it among the 15 biggest generic-drug makers in the industry today. It is now the second- biggest, even before the Forest transaction, with a market value of about $35 billion.

Bisaro said his company has assessed going after other major generics companies, but all offered obstacles to a deal.

In January, he ticked off the hurdles in an interview with Bloomberg News: Teva Pharmaceutical Industries Ltd., with its strong Israeli heritage, would resist a foreign buyer, while Mylan Inc.’s leadership wanted to stay independent, he said. Novartis AG was unlikely to sell its Sandoz unit, according to Bisaro, and Pfizer Inc. was at least three years away from selling its generics line.

Clear Path

After Saunders and Bisaro met in San Francisco, though, the process proceeded smoothly, Saunders said.

“We didn’t run a full sales process,” he said. “This was a situation that came on very quickly as Paul and I got to know each other.”

It moved so quickly, in fact, that Bisaro and Saunders say they haven’t fully figured out what Saunders’s role will be at the combined company, beyond his presence as a board member.

While both say they’re committed to the extended company, “it’s way too early to know what roles we’re going to have and what’s going to work out,” Bisaro said. “For the foreseeable future, though, I see myself actively engaged in the business.”

The company, meanwhile will re-work its executive compensation as the acquisition takes hold, Bisaro said.

“We have to,” he said. “We’ve moved to a different level. We’ll be able to put in place a program that keeps people motivated.”

It’s the second time Bisaro and his team will see substantial profit from an acquisition. After the deal to buy Warner Chilcott was announced in May, moving the company’s headquarters to Dublin, Ireland, Bisaro and other executive received a $115 million payout in early-vested stock and retention bonuses that otherwise would have been taxed by the U.S.

It was an unusual case of executives at an acquiring company being paid out after a deal. Actavis said it was proper, and needed to avoid penalizing its team for doing a deal and incurring tax penalties.