The top price of Kenya's benchmark coffee grade AA dropped to $318 per 50-kg bag at auction from $433 per bag at last week's sale, the Nairobi Coffee Exchange (NCE) said on Tuesday.
Although Kenya is a relatively small producer, its high quality beans are valued by roasters for blending with those from other countries.
A bag of grade AA COF-AA-KE sold for $318-$176, compared with $433-$219 at last week's sale, while a bag of grade AB COF-AB-KE fetched $252-$131 per bag, from $244-$123 at the previous auction, the exchange said.
It was not immediately clear what pushed the price of grade AA coffee lower. Calls to the Kenya Coffee Producers and Traders Association, which sends out the NCE's report, went unanswered.
Some 21,453 bags of coffee were offered for sale and only 5,257 bags were bought. Last week, 21,487 bags were offered for sale, with 7,054 sold.
The beans fetched $906,251 with an average price of $141.35 per bag, the exchange said. Last week, beans sold at the auction fetched a total of $1.36 million with an average price of $157.61 per bag.