Shares in New Britain Palm Oil tumbled to a three-year low after the group revealed that its main site in Papua New Guinea had been plagued again by rains – despite having assured investors that it was ready for inundations this time.

The producer of sustainable palm oil - which last month said that it was "better prepared to cope with wet weather in the January-to-April period" – revealed that its performance had again been "negatively impacted" by heavy rainfall.

Indeed, its processing volumes had fallen 5% behind those for the same period of last year, when the first-quarter crush was in turn down 8.3% year on year.

New Britain Palm Oil shares stood 6.3% lower at 420p in late deals in London, after touching 415p earlier, their lowest since January 2010.

'Irretrievably lost'

The group said that its some areas of West New Britain Province in which it operates will have received 3 metres of rain by the end of the quarter, "well above average levels".

"High rainfall inhibits the ability of our workforce to collect fresh [palm] fruit bunches from the field, primarily because of the resulting transportation and access difficulties," New Britain Palm Oil said.

"Harvesting rounds have been extended in the worst affected areas to limit fruit loss.

"However, it is expected that some fruit will be irretrievably lost in the field during this period," with oil extraction rates reduced too.

The company said it had been "working closely" with state officials on emergency repairs to damaged roads and bridges.

Broker downgrades

The comments come less than a month after Antonio Monteiro De Castro, the New Britain Palm Oil chairman said that the group had "put in place certain measures to ensure that 2013 will be a more robust trading year.

"Operationally we entered 2013 better prepared to cope with the wet weather in the January to April period.

"Harvest intervals are under control at all sites and adequate labour numbers are on hand to cope with temporary harvesting delays caused by bad weather," he said, as the group unveiled a 70% drop in 2012 profits largely blamed on early-year rainfall denting production.

Thursday's statement received a cool welcome from analysts at Shore Capital, who cut their rating on New Britain shares to "sell" from hold, and Peel Hunt, which reduced its recommendation to "hold" from "buy".