Quito, Oct 20 (IANS/EFE): Ecuador will auction contracts for new Amazon oil blocks believed to contain as much as 1.6 billion barrels, Non-Renewable Natural Resources Minister Wilson Pastor said Friday.

Three of the 16 blocks will be directly awarded to foreign state oil companies that will partner with Ecuadorian state oil firm Petroamazonas.

The minister said the winning bidders are expected to invest around $1.2 billion in the blocks.

The interested companies include Spain's Repsol, Italy's Eni and China's Andes Petroleum and Sinopec, as well as Peruvian, Colombian, Mexican, Turkish, Vietnamese and Indonesian oil firms.

Contracts for a total of 21 blocks were initially to be awarded, but that number was reduced to 16 and the start of the bidding process was pushed back from October to November to allow time to work out agreements with communities that live in those areas.

Once the bidding process is launched, interested companies will have until May 30, 2013, to prepare their bids. Ecuador's government will then evaluate them with a view to signing new contracts next September.

Oil is Ecuador's main export product and also a key source of government revenue.