Activity in Russia's manufacturing sector expanded at its slowest pace in six months in January, a business survey showed on Thursday, driven by another dip in new export orders.

The S&P Global Purchasing Managers' Index (PMI) for manufacturing fell to 52.4 in January from 54.6 in December, staying above the 50 mark that separates expansion from contraction.

New export orders have now contracted for three months in a row.

"Companies saw a faster drop in new export orders," S&P Global said. "New sales to external markets fell at a modest rate that was the quickest in six months, as demand from key export markets waned."

Moscow is spending heavily on manufacturing, pouring cash into the defence sector to ramp up military production following its February 2022 invasion of Ukraine. The sector's growth since then has been largely predicated on domestic demand.

Input costs slowed in January, S&P Global said, despite reports of input shortages and transportation delays. But firms continued to increase selling prices at a historically robust pace.

Meanwhile, expectations for future output remained elevated.

"Optimism reportedly stemmed from planned investment and hopes of further upticks in client demand," S&P Global said. (Reporting by Alexander Marrow; editing by Christina Fincher)