Oil and gas producer Harvest Natural Resources Inc said near-term liquidity constraints could hurt its ability to negotiate best possible terms to sell itself or its assets, sending its shares down as much as 32 percent.

Harvest Natural said in September that it was in exclusive talks to sell itself to Argentina's Pluspetrol in a deal valued at about $373 million including debt.

However, Harvest Natural said on Tuesday that the time frame for exclusive talks had passed. The company is yet to strike a deal.

Harvest Natural shares were down 27 percent at $3.28 in early afternoon trade on the New York Stock Exchange.