Tunisian state-run Office des Cereales said on Tuesday it is seeking to buy at least 50,000 tonnes of soft wheat.
It set Wednesday at 0830 GMT as a deadline for the tender but said bids will be valid until 1500 GMT Wednesday.
Loading dates would be between May 15 and June 25 if the origin is from Eastern Europe, May 10 and June 20 if from Western Europe, May 1 and June 10 if from North or South America, including the US, and between April 20 and May 30 if from Australia.