Treaty reinsurance written in the London company market fell 6% last year, according to data released by the International Underwriting Association. Total premiums of £11.270bn were recorded by the sector in 2025, compared to £11.985bn the previous year.

Just over a quarter (26%) of premiums written in London in 2025 were treaty reinsurance, with direct and facultative contracts making up the remaining 74%. These proportions are almost unchanged from the previous year and consolidate a steady increase in the relative importance of treaty business over recent years. In 2020, treaty premiums written in London were £5.320bn, representing 19% of the market total.

Property is the largest class of treaty reinsurance business written in London, accounting for premiums of £3.083bn in 2025. Motor treaties comprise a further £2.393bn, followed by marine at £1.555bn and liability on £1.365bn.

Scott Farley, IUA director of communications, said: “The overriding message we have received from IUA member companies this year is one of disciplined underwriting. The figures from the latest London company market premium statistics survey clearly illustrate a shift to a more competitive pricing environment, compared to the hard market cycle observed in recent years.

“Whilst there has been a fall in treaty reinsurance premiums over the past 12 months, the market aggregate total is still more than double the figure from six years ago. There are also variations between different business classes and geographical regions. Where growth has occurred, however, it is described as ‘deliberately selective’.”

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