UPDATE 1-S.Africa's March CPI at 9-month high on food

* Food inflation quickens sharply

* Inflation at highest since June 2010 (Adds details, background)

JOHANNESBURG, April 20 (Reuters) - South Africa's headline consumer inflation accelerated more than expected to a nine-month high in March, mainly driven by higher food prices.

Statistics South Africa said on Wednesday consumer inflation quickened to 4.1 percent year-on-year in March from 3.7 percent in February. Economists in a Reuters poll expected 3.9 percent.

On a month-on-month basis, inflation went up to 1.2 percent from 0.7 percent, also above market expectations of 0.1 percent.

The main driver was food inflation, which quickened to 5.0 percent year-on-year, and was up 1.2 percent month-on-month from -0.1 percent in February.

The South African Reserve Bank (SARB) expects inflation to remain within its targeted band of between 3 and 6 percent until the end of 2012 but says food and fuel prices are the main upside risks to the inflation outlook.

"This print will serve to jolt the market. CPI is rising rapidly, notwithstanding South Africa's generally weak economic recovery," said Razia Khan, head of Africa research at Standard Chartered in London.

"The SARB will not overreact of course, but this print will set the market thinking about how soon we might need to see tightening in South Africa," she added.