The maximum price of the top grade Kenyan tea, Best Broken Pekoe Ones (BP1s), edged lower at auction this week, Africa Tea Brokers (ATB) said in a report. Producers offered 10.6 million kg of tea during the sale and 15.42 percent did not get buyers, ATB said. Kenya is the world's leading exporter of black tea and the crop is a major foreign exchange earner for the economy.