Emerging-market economic growth was probably the weakest since September 2011 last month as global demand for manufacturing and services declined, HSBC Holdings Plc said, citing a survey of purchasing managers.

The HSBC Emerging Markets Index, which is compiled by London-based Markit Economics and tracks conditions at more than 5,000 companies, fell to 51.3 in April from 52.5 in March, HSBC said Tuesday in a report. A value above 50 indicates expansion and below 50 signals contraction.

The International Monetary Fund trimmed its global growth forecast April 16 as the euro-region recession extends into a second year, dragging down the rest of the world. The global economy will expand 3.3 percent this year, the Washington-based lender said, cutting its prediction a fourth time.

"Weaker economic growth across most advanced markets is now being felt in the emerging world as well," said Frederic Neumann, HSBC’s co-head of Asian economic research. "Slower growth raises the vulnerability of emerging markets to a broader shake-out in advanced economies, whether a deeper slump in Europe or renewed financial stress that would quickly propagate across emerging markets as well."

The MSCI Emerging Markets Index has fallen 0.4 percent this year, compared with a 14 percent gain for the S&P 500.

The HSBC Emerging Markets Future Output Index, which gauges company executives' expectations for output in a year, fell for a second month to its weakest since September, HSBC said.