London cocoa futures shot up for a second session on Thursday on fund buying, though December failed to break through the psychologically important 1,000 pound level, traders said.
Some dealers expect it to make further attempts in coming weeks until more is known about the state of the new crops in Ghana and Ivory Coast in September.
"It's the time of year when any talk of lower-than-expected crops make people nervous," said one trader. In addition, strong technicals are drawing in funds and there's an absence of selling, he added.
Second-month December surged to 998 pounds in afternoon trading - the highest since a peak of 1,008 on August 5 - before retracing to end 44 pounds or 4.6 percent higher at 994 pounds a tonne.
Volume on December was 7,014 lots from a total of 13,445.
Bean values in New York also jumped, surging as much as 5.5 percent to a two-week high on fund and speculative buying.
Cocoa arrivals at ports in Ivory Coast reached 1,349,188 tonnes between the start of the 2003/04 (Oct-Sept) campaign and July 25, official data from the Coffee and Cocoa Bourse (BCC) said on Thursday.
That compared with 1,348,935 tonnes delivered to ports during the same period of the 2002/2003 season, a Reuters report from Abidjan said.
Ghana's Cocoa Board (Cocobod) has 632,000 tonnes of bagged and sealed cocoa beans in its warehouses, a senior official at the finance ministry said on Thursday.