A nationwide index of non-manufacturing economic activity is expected to show activity slowed in May, but less so than in April, according to economists polled by Reuters.

A poll of 69 economists by Reuters produced a median forecast of 45.0 for the May ISM non-manufacturing business activity index, up from 43.7 in April.

The lagged effect of stronger Q1 retail sales should lift the index, said Ian Shepherdson, chief U.S. economist at High Frequency Economics in Valhalla, New York.

The Institute for Supply Management will release the monthly data at 10 a.m. EDT on Wednesday.

A sampling of forecasts and analysis on the upcoming data follows:

MICHAEL MORAN, CHIEF ECONOMIST, DAIWA SECURITIES AMERICA, NEW YORK:

Forecast: 44

Most of the economic numbers have been reporting a slower rate of decline in the economy and I expect a similar kind of reading in this measure. That would mean an increase in the index reading, but still a reading below 50 percent, signifying contraction -- but slower contraction.

KENNETH KIM, ECONOMIST, STONE AND MCCARTHY RESEARCH ASSOCIATES, PRINCETON, NEW JERSEY:

Forecast: 44.7

We're looking for a reading of 44.7 for the May non-manufacturing ISM index, up one point. Things are getting less worse so that in itself is an improvement. I don't expect to see any major movement in the non-manufacturing ISM in the upcoming report, given what we've seen of other purchasing reports on the manufacturing side. The non-manufacturing index generally follows the contours of the manufacturing sector.

IAN SHEPHERDSON, CHIEF U.S. ECONOMIST AT HIGH FREQUENCY ECONOMICS IN VALHALLA, NEW YORK

Forecast: 46

The lagged effect of stronger Q1 retail sales should lift the index to 46 from 43.7.

(Polling by Bangalore Polling Unit)

(Editing by Leslie Adler)

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