(Recasts with suspension of strike)

By Robin Pomeroy and Silvia Aloisi

ROME, Dec 12 (Reuters) - Unions representing striking Italian truckers said on Wednesday they were suspending a three-day-old blockade that has cut off fuel supplies, closed factories and stopped food reaching the shops.

The two main unions behind the strike said they decided to halt the protest after the government promised to address their main concerns -- reduce diesel costs, crack down on cheap foreign competition and tighten rules on haulage contracts.

"The matter is resolved," Enrico Letta, a close adviser to Prime Minister Romano Prodi, told reporters.

"We are confident that in the next few hours the situation will go back to normal across the country." The strike, in protest against high fuel costs and poor working conditions, meant supermarket shelves usually filled with fresh fruit and vegetables were going bare and most filling stations were closed.

Using hundreds of vehicles to block motorways at strategic points since Monday, the truckers brought parts of the economy to a standstill. Car maker Fiat closed factories for lack of parts and told thousands of workers to stay at home.

The protests continued on Wednesday, despite an injunction from the Transport Ministry, which had ordered the drivers to go back to work from midnight on Tuesday and said their strike was illegal.

Rome's main fruit and vegetable market was almost empty on Wednesday morning and food trade body Federalimentare said the strike was costing the sector 210 million euros ($308.4 million) a day in lost perishables.