The Stanbic Bank Kenya Purchasing Managers' Index (PMI) fell to 47.2 from 49.2 in March. Readings above 50 signal growth and those below a contraction.

It is the third straight month the reading was below 50.

"The cost-of-living crisis continued to hinder business performance, according to survey panelists, while an associated bout of political unrest led to a marked drop in client demand," a text accompanying the survey said.

On Tuesday, Kenya's opposition resumed anti-government protests after a one-month pause over high living costs and alleged fraud in last year's national election, which its leader Raila Odinga lost to President William Ruto.

Odinga suspended the demonstrations in early April, agreeing to talks with Ruto's representatives. But Odinga later announced the protests would resume, accusing the government of not negotiating in good faith.

"Despite continued growth in export sales, deteriorating domestic market conditions due in large part to higher costs and political protests dampened business activity and domestic demand as cost pressures continued to rise," Mulalo Madula, an Economist at Stanbic Bank, said.

Inflation dropped to 7.9% year-on-year in April from 9.2% in March, data from the statistics office showed.

(Reporting by George Obulutsa; editing by John Stonestreet)