London Stock Exchange Group has revealed a jump in sales and profits for the first half of 2021 but warned that it could face higher costs for the rest of the year.

The financial data firm and market operator said higher trading was driven by a “good performance across all divisions”.

It told shareholders on Friday that total income for continuing operations increased by 4.6% for the six months to June.

Meanwhile, it said its pre-tax profit for the period almost doubled to £510 million, compared with £262 million a year earlier.

However, the FTSE 100 firm warned investors that it expects further cost increases in the second half of 2021, driven by Covid-related costs such as travel and expenses related to legacy IT and inflation.

It also said that synergies from the integration of Refinitiv – the data business it bought for £27 billion earlier this year – are running ahead of schedule.

LSEG hailed “good progress” regarding the incorporation of Refinitiv and said it has raised its expected cost savings in 2021 from the deal to £125 million from previous guidance of £88 million.

Group chief executive David Schwimmer said: “LSEG has delivered a good financial performance in the first half of the year, reflecting revenue growth across all divisions.

“We continue to invest in projects that enhance our customer offering and deliver a more scalable and efficient business, particularly in data and analytics.

“This will support our revenue growth ambitions and lead to further operating margin improvement.

“The reduction of leverage during the period reinforces our strong financial position and, with our mix of world-class assets and unique positioning in growing markets, we look forward to further progress during the rest of the year.”

Bosses also said they will pay an interim dividend of 25p per share, representing a 7% rise.

Shares were 3.8% higher in early trading on Friday.