Communist officials decreed Friday that private farmers and co-operatives can use up to 40 hectares of idle government land as President Raul Castro works to revive Cuba's floundering agricultural sector.

The law published in the Communist Party newspaper Granma did not say how much state land will be turned over to private hands and gave no indication of how many Cubans might apply.

But it described the measure as a way to help Cuba solve the problem of underused land while cutting food imports that are expected to cost the government $2 billion US this year.

Landless Cubans can be given a bit more than 13 hectares while those who already have fully producing plots can add enough state land to bring their total holdings to 40 hectares.

Existing state farms, co-operatives and state factories also can apply for underused land.

Ownership will stay with the state. Private farmers can get concessions of up to 10 years, renewable for another 10.

Co-operatives and companies can have renewable 25-year terms. And all will have to pay taxes for the lands, though the decree gave no details.

While the individual parcels are small, the widespread transfer of farmland from public to private hands could change the face of farming in a country where the government controls well over 90 per cent of the economy.

The decree noted that Cuba now suffers from "a considerable percentage of idle state lands," making it necessary to grant concessions "with the objective of elevating food production and reducing importation."

Government statistics released last month show that the percentage of fallow or underused Cuban farmland increased to 55 per cent in 2007, up from 46 per cent in 2002. Just 29 per cent of land on state farms is actively used.

After Fidel Castro took power in 1959, the government expropriated many large farms and agricultural holdings, while allowing thousands of small farmers to keep their plots and sell their produce to the state.

The new measure doesn't say where farmers will sell their output, but nearly all private farmers now are required to sell most of their produce — beyond what they eat themselves — to the state.

Friday's decree spells out details of a plan announced in March, when officials told state television they had begun lending more small plots to private producers of tobacco, coffee and other key cash crops.

Raul Castro, 77, has made increasing food production and reducing dependence on imports a priority since succeeding his brother Fidel in February.

The government earlier gave more autonomy to regional farm authorities and it is paying private farmers more for milk and meat.

State-owned farms now hold just over one-third of Cuba's agricultural land — down from about 70 per cent two decades ago. The rest is worked by small farmers and co-operatives, many of them state-organized.