On Monday, Pfizer the U.S. based drug maker announced that it had made the decision not to split into two companies that would have been publicly traded through separating its patent protected medicines that are branded with its low growth generics.

Instead, the pharmaceutical giant, with the two being operated separately within Pfizer, the company already was accessing a number of benefits of a split, while at the same time retaining the strength operationally, efficiently and the financial flexibility of having just one company, said Ian Read the CEO.

Over time, the potential gap between the market valuation of Pfizer and an implied market valuation of its two parts has narrowed, said Frank D’Amelio the CFO.

Therefore, said the CFO, the company concluded that the splitting of the two businesses at the current time would not help the cash flow generation and the disruption of the operations and increased costs due to the split would result in being value destructive.

Shares of Pfizer were down by 1.3% in Monday premarket trading. The company for a number of years has weighed whether splitting into two, made sense, due largely because its medicines that are patent protected routinely have growth in sales, while its generics portfolio usually posts declines in sales.

Investors have shifted focus to if Pfizer would be splitting after the business ended a deal of $160 billion to acquire Allergan the Irish drug maker this past April due to new rules for tax inversion in the U.S.

On Monday, Pfizer said the decision not to make a split of its two businesses would not have any impact on its forecast for 2016, and that it kept the option to split down the road.

In August, Pfizer made the announcement that it agreed to acquire Mediation a drug maker that specializes in cancer treatment for a price of $14 billion so it could gain new access to Xtandi the blockbuster drug for treating prostate cancer.

The deal for Medication spotlights Pfizer’s shift in strategy for M&A from lowering its taxes, which was the rationale that prompted the Allergan failed deal, to strengthening a lineup of branded drugs, led by very lucrative treatments for cancer.

Last year, Pfizer paid over $15 billion to acquire Hospira, which sells hospital products that are generic and is developing new biosimilars that compete with biotech injectable drugs.