NAIROBI - Kenyan private sector activity expanded in September for the first time since March, a survey showed on Wednesday, as business got back on track after a peaceful presidential election the previous month.

The S&P Global Kenya Purchasing Managers' Index (PMI) jumped to 51.7 during the month, from 44.2 in August, entering above the 50.0 mark denoting growth in activity for the first time in six months.

"Business conditions saw a renewed uptick in September as concerns over post-election disruptions faded," said Mulalo Madula, an economist at Stanbic Bank, which is involved in the survey.

President William Ruto was sworn in office on Sept. 13 after he narrowly won an Aug. 9 vote, the outcome of which was upheld by the Supreme Court after the losing candidate lodged a challenge.

"Firms have signalled a strong rebound in output, while the sharp increase in demand also meant firms stepping up purchasing activities and stockpiling, with some firms emphasizing concerted efforts to avoid future shortages," Madula said.

Firms are however concerned that increased demand and higher retail prices of fuel, following the removal of subsidies, could feed inflationary pressures, driving up their costs, Madula said.

(Reporting by Duncan Miriri; Editing by Susan Fenton)