Its finance head Daniel Schmucki told Reuters the group could also do more acquisitions to boost growth, but wouldn't comment on a Reuters report that SIX was among bidders for the bond-trading platform of the London Stock Exchange's (LSE) Borsa Italiana unit.

"The integration of BME doesn't keep us from looking at opportunities," Schmucki said in an interview.

SIX said in a statement that the COVID-19 pandemic had a negative impact on some of its business areas, notably on ATM and card transactions, in the first half, but market volatility caused a strong increase in trading turnover.

The company's operating income rose 7.6% to 593.4 million Swiss francs in the first half of 2020 excluding the contribution from BME. Including BME since closing of the deal on June 16, operating income was 624.1 million francs, SIX said.

SIX bought a controlling stake in Spanish Bolsas y Mercados Espanoles (BME) for 2.57 billion euros ($3.03 billion), forming the third largest operator of financial market infrastructure in Europe.

SIX divested a 6% stake in French payments company Worldline in April to help fund the BME deal.

It said on Tuesday its remaining 16.3% stake in Worldline was strategic and it intended to remain a shareholder for the mid to long term. It also said it continued to support Worldline's offer to take over rival Ingenico.

(Reporting by Silke Koltrowitz and Oliver Hirt; editing by Brenna Hughes Neghaiwi)