Glaxo SmithKline CEO Andrew Witty has become the first pharmaceutical or chemical company executive to come out in favor of the UK remaining in the EU, although business leaders in other segments have begun to speak out as the June referendum over a possible “Brexit” nears.

At a press conference to present the drugmaker’s Q4 2015 financial results, Witty said it’s better to remain in the EU and reform it.

“We regard Europe as a significant economic bloc, it is important to us from a regulatory perspective, but it also creates some levels of predictability. Could it be improved? Of course it could be improved, we would encourage the government to work hard to improve it, but we believe it is better to be in and improving it than to be on the outside and trying to plot a new course,” the CEO said.

At the conference, Witty also answered another question that analysts and other industry observers have frequently asked. He said the company is not planning to sell its consumer health business, a GSK-controlled joint venture with Switzerland’s Novartis – as urged by investors such as powerful fund manager Neil Woodford – at least not in the near future.

The British company picked up consumer health and vaccines, along with other businesses, in an asset swap with Novartis.

While not ruling out a spin-off at some point in the future, Witty said it would be “unwise” to make a definitive decision now or in the next several years, adding: “When you look at the uncertainty of global markets, having a more balanced set of businesses is exactly the right course for us to be following.”

As at other major chemical-pharmaceutical producers such as Dow, DuPont or Syngenta, shareholders have been pushing GSK to streamline its portfolio. Some have even called for Witty’s resignation if he does not make a move.

The drugmaker’s results for the fourth quarter show a 6% rise in sales to £24 billion, beating analysts’ expectations despite a loss of nearly £270 million.

While sales of the asthma drug Advair continued to decline on the back of generic competition, GSK said revenues from the new Breo and Anoro inhaled lung drugs have risen in key markets. The meningitis and other vaccines, along with new HIV drugs and the consumer healthcare business, all performed strongly.