Figures showed that the seasonally adjusted service Purchasing Managers' Index (PMI) stood at 50.4 in April, up from a 32-month low of 48.9 in March.
Meanwhile, the seasonally adjusted all sector output index posted 50.9 in April, up from 50.0 in March.
The survey suggested that manufacturing was the strongest sector in April, while services and construction signalled a slight expansion.
Chris Williamson, chief business economist at IHS Markit, said, "Although the service sector joined construction in reporting a return to growth, in both cases the expansions were only marginal."
"The resulting rise in business activity signalled collectively by April's PMI surveys was only marginal, suggesting the economy remained more or less stalled at the start of the second quarter," Williamson added.