Global investment in London office space remained strong at the start of the year, but is expected to dip in the run-up to the EU referendum next month.

A total of £3.5bn was invested in central London in the traditionally subdued first three months of the year, on a par with the same quarter in 2015, according to data from the real estate advisory firm CBRE. The figure was down from £4bn in the fourth quarter of 2015, which was particularly strong.

CBRE said there were 43 transactions in the first quarter, the lowest number since 2010. But the number of large deals above £100m hit 14, the highest first-quarter figure since records began in 1985. Among the biggest deals were the government’s £371m sale of a stake in the King’s Cross development to Australia’s largest pension fund, and Great Portland Estates’ sale of Savills’ headquarters to Germany’s Deka Immobilien Investment for £216m.

Jamie Pope, the executive director of London capital markets at CBRE, said: “Some investors are experiencing a degree of political and economic uncertainty at the moment, so it’s heartening to report that this hasn’t caused much in the way of turbulence in the London office market in the first quarter of the year. Yields are stable.

“Nevertheless, we are already seeing some buyers hold off on deals until they know the result of June’s EU vote, so we expect to see the second quarter’s transaction volumes dip, before bouncing back in the second half of the year, provided Britain stays in the EU.”

The Royal Institution of Chartered Surveyors said last week there had been an easing in international demand for UK office, industrial and retail property since the referendum was confirmed last spring.

The CBRE said international investors continue to dominate the market and were involved in just over two-thirds (67% of all transactions, down from 71% in the fourth quarter. Taking advantage of the weak pound, they poured more than £2.4bn of investment into London offices.

Kevin McCauley, head of London research at CBRE, said Chinese investors, who stayed away after China’s stock market turmoil last summer, returned to the capital towards the end of the year and into 2016 in search of a haven.

He said: “London has been the key beneficiary of investors looking to diversify away from risk – economic or social – since at least 2013.” He pointed to transparent pricing and the relative ease of access to the London office market, as well as a shortage of new office space, which means rents are expected to keep growing.

“A lot of cities in Asia and mainland Europe and New York are significantly more expensive in yield terms than London is.”