UPDATE 1-French fishermen step up protest over fuel costs

(Adds blockade of petrol terminal in paragraph 2)

BORDEAUX, France, May 18 (Reuters) - French fishermen prolonged a blockade of La Rochelle port on Sunday to protest against rising fuel costs that comes as President Nicolas Sarkozy prepares for a week of nationwide demonstrations.

Fishermen said they had blocked the ports of Chef de Baie, Rochelle's Old Port and the Minimes port in western France. They also blocked La Rochelle's petrol terminal on Sunday evening.

Earlier in the week, fishermen also cut off access to the nearby Atlantic ports at Ile d'Oleron and La Cotiniere.

Record oil prices of more than $120 a barrel have led to higher fuel costs for fishermen, impacting their profit margins.

French truckers have also protested over the situation and staged demonstrations in southern France last week.

Fishermen forced Sarkozy to increase aid to the fishing industry last November after blocking off various ports and oil depots during a six-day strike.

But they say this has proved insufficient since the cost of fuel has continued to rise.

French Agriculture Minister Michel Barnier has said the state has handed over 30 million euros ($46.4 million) of aid to the fishing industry this year, with another 23 million on the way.