FRANKFURT (Reuters) - Germany's Merck KGaA (>> Merck KGaA) expects sales to grow by around 5 percent in its core operations over coming years, helped by its pipeline of prospective new drugs, its chief executive was quoted saying by weekly Euro am Sonntag.

Merck, which makes drugs, chemicals and laboratory supplies, posted group sales of 11.3 billion euros ($12.5 billion) in 2014, up 5.5 percent from the previous year.

After the $17 billion acquisition of Sigma-Aldrich Corp (>> Sigma-Aldrich Corporation), expected to be wrapped up around mid-year, the group aims to focus on organic or self-generated growth, CEO Karl-Ludwig Kley told the paper, adding he expects the drug pipeline to become the group's main driver.

Kley said that after years of setbacks in drug development, the division was now on track thanks to restructuring, expanding into the United States and biotechnology and thanks to a cancer drug deal with Pfizer (>> Pfizer Inc.).

Merck struck the alliance over cancer immunotherapy drugs in November, triggering an upfront payment of $850 million by the U.S. drugmaker.

The two companies will develop Merck's so-called anti-PD-L1 agent as a single therapy as well as in combinations with Pfizer's and Merck's portfolio of approved and experimental drug candidates.

Merck said earlier this week it sees adjusted core earnings (EBITDA) of between 3.45 billion euros ($3.9 billion) and 3.55 billion for 2015, implying an increase of between 1.8 and 4.8 percent, before including Sigma-Aldrich.

(Reporting by Kirsti Knolle; Editing by David Holmes)

Stocks treated in this article : Pfizer Inc., Sigma-Aldrich Corporation, Merck KGaA