LONDON (Reuters) - British construction firms turned their most optimistic in two years as the prospect of interest rate cuts raised hopes of a turnaround in the sector, a survey showed on Tuesday.

The S&P Global/CIPS UK Purchasing Managers' Index's headline measure of the construction industry improved to 48.8 in January from 46.8 in December, its highest since August 2023 although still in no-growth territory.

Economists polled by Reuters had forecast a smaller rise to 47.3.

Tim Moore, Economics Director at S&P Global Market Intelligence, said customer demand appeared close to turning a corner as the economy picked up after a weak end to 2023.

"UK construction companies seem increasingly optimistic that the worst could be behind them soon as recession risks fade and interest rate cuts appear close on the horizon," Moore said.

Construction firms said higher shipping costs pushed up prices paid for raw materials for the first time since last September.

There have been signs in other surveys that disruption to shipping in the Red Sea has delayed deliveries to British manufacturers.

Tuesday's PMI survey chimed with data from the Royal Institution of Chartered Surveyors, published last week, that showed a brighter outlook for the construction sector.

S&P Global said residential house-building continued to be the biggest drag on activity although the pace of decline was the softest since March last year.

Output in civil engineering was close to stabilisation and commercial building also shrank by less than in December, S&P Global said.

Overall new orders growth showed the slowest rate of decline since they started to contract in August 2023 and employment fell only slightly.

The wider all-sector PMI, which includes previously released services and manufacturing figures, rose to its highest in eight months at 52.6 from December's 51.7.