The S&P Global Kenya Purchasing Managers' Index (PMI) jumped to 51.6 in December from 50.9 a month earlier. Readings above 50.0 signal growth in business activity, while those below that point to a contraction.

"Firms that saw a rise in activity cited higher sales, increased marketing, favourable weather conditions and slowing inflationary pressures," S&P Global said in comments accompanying the survey.

The survey showed business activity improved in the agriculture, manufacturing and wholesale and retail sectors, while it fell in services and construction.

Inflation eased to 9.1% year-on-year in December from 9.5% a month earlier, data from the statistics office showed.

"Moderate inflation is likely to be one of the few positive factors in the second half of 2023, with fewer supply chain disruptions, favourable weather conditions and lower energy prices," Mulalo Madula, an economist at Stanbic Bank, which is involved in the survey, said.

"However, idiosyncratic factors, including taxes, are likely to dislocate inflation in the first half of the year."

(Reporting by George Obulutsa; Editing by Susan Fenton)