MOSCOW-Russia's private-sector services activity continued to contract in May, slumping to a five-year low and signaling further hurdles for economic recovery, a survey of purchasing managers by HSBC showed Wednesday.

The Services Purchasing Managers' Index inched down to 46.1 in May from 46.8 in April, staying below the critical 50-point mark that separates growth from contraction for the third month in a row.

The services sector data comes two days after an HSBC survey showed manufacturing activity continued to contract in May albeit at a slower pace.

"Overall, the PMI survey signals another leg down in the Russian economy is most likely in the coming months before the situation can start improving, if the resumption in new order growth in manufacturing continues," said Alexander Morozov, chief economist at HSBC in Moscow.

Hit by massive capital outflows as a result of the Ukrainian crisis and Moscow's political standoff with the West, Russia's economy is likely to post its weakest growth since the global financial crisis. The economy ministry warned that gross domestic product may even contract this year if net capital outflow remains at a level seen in the first quarter, when Russia drained more than $60 billion.

The output decline across manufacturing and services sectors in May reflect the deterioration in business conditions, underlined by a decrease in employment for the eleventh consecutive month.

"While demand in manufacturing showed signs of recovery, the service sector marked a deterioration of key economic activity indicators," Mr. Morozov said.

The services sector the outlook for the next 12 months continues to be weak due to political uncertainty and accelerating inflation, although there was some improvement in the outlook in May due to an expected recovery in demand.

Write to andrey.ostroukh@wsj.com