No purchase has yet been made and results are expected later on Wednesday, they said.
The offer priced at $253.47 a tonne was for 25,000 tonnes.
This was followed by other soft wheat offers for other shipment positions in the tender at $255.33, $255.63 and $256.40 a tonne c&f.
The lowest offer in the tender for 92,000 tonnes of durum wheat was $290.29 a tonne c&f.
Lowest offer in the tender for 75,000 tonnes of animal feed barley was $229.54 a tonne c&f.
The Tunisian agency does not always purchase the lowest offer if other conditions connected with the offer are seen as unattractive.
The durum was sought in three 25,000 tonne consignments and one of 17,000 tonnes, the soft wheat in four 25,000 tonne consignments and the barley in three 25,000 tonne consignments.
All were sought for shipment between March 15 and April 25 depending on origin supplied.
In its last reported tender on Jan. 23, Tunisia's grains agency purchased around 100,000 tonnes of soft milling wheat and 50,000 tonnes of feed barley.