Cocoa purchases declared to Ghana's industry regulator Cocobod stood at 667,000 tonnes by July 2, down by around one-fifth from the previous year, two government sources told Reuters on Friday.

The world's second-largest producer has extended its main crop-buying period, and purchases could continue until the 2014/15 season ends in September, buyers said.

Ghana sharply lowered its output forecast to 750,000 from one million tonnes due to a drop in the Oct-June main crop yield.

The West African country bought around 900,000 tonnes of cocoa in the previous crop year.

"The purchases are still lagging... we are still below 700,000 tonnes," a government source said, suggesting that Cocobod could miss the revised 750,000-tonne target.

Cocobod has yet to announce formally, the start of the smaller July-Sept light crop purchases which is mainly discounted to local processing companies and buyers say the regulator might not do so.

"The indications are that Cocobod does not see the need to break in between the main crop and the light crop. They intend to continue the purchases until the end of the crop year," said one buyer whose company purchases around 10 percent of Ghana's total crop yearly.