British business activity weakened in September as the S&P Global UK Services PMI fell to 51.7 from 52.5 in August, its lowest level in three months and below the 52.0 forecast in a Reuters poll. Services companies reported their fastest increase in selling prices in four months, while energy-related cost pressures accelerated amid the escalating war in Iran. S&P Global said the survey indicated quarterly economic growth of about 0.1%, down from 0.4% in the second quarter. The data complicate finance minister John Healey’s efforts to maintain an upbeat assessment of the economy before his first budget next month, with economists warning that higher government borrowing costs and inflation could weaken the outlook. Financial markets on Tuesday priced in roughly a 60% chance of a Bank of England (UK central bank) rate increase on November 5, the week after the October budget. Manufacturing provided a brighter note: its flash PMI rose to 52.0 from 51.7, supported by stronger domestic orders, while sector optimism reached a seven-month high. The composite PMI, combining manufacturing and services, fell to 51.7 from 52.5.