UPDATE 1-GrainCorp H1 profit slides 43 percent on poor harvest

(Adds quote, context on ADM bid and El Nino threat)

SYDNEY , May 15 (Reuters) - Australia's largest listed agribusiness GrainCorp posted a sharp fall in profit on Thursday on lower east coast grain production and could also face difficult conditions this year with the expected onset of an El Nino weather pattern.

A planned A$2.8 billion ($2.62 billion) takeover of GrainCorp by U.S. agribusiness giant Archer Daniels Midland Co to improve its access to fast-growing Asian markets was rejected last November by Australia after Treasurer Joe Hockey said it was not in the national interest.

However, Andrew Robb, Australia's Minister for Trade and Investment, said in March that "there may be another opportunity at some stage" for ADM to pursue GrainCorp. He also said he was open to ADM increasing its holding of GrainCorp to 25 percent from just below 20 percent currently.

GrainCorp said its net profit for the six months to March 31 was A$50 million ($46.9 million), down 43 percent from A$88.2 million a year ago. Most analysts do not forecast half year profits, but Thomson Reuters I/B/E/S consensus forecast pegs the company's full-year net profit at a four-year low of A$93 million, down from A$174.5 million a year ago.

Shares in GrainCorp fell more than 1 percent after the announcement of a profit slide, underperforming a slight fall in the benchmark index.

The bulk grain handler attributed the fall earnings to a smaller grain harvest from Australia's east coast, where it has most of its business.

"While the intense competition for a smaller crop also means that GrainCorp Marketing's result was lower year-on-year, it is pleasing that this business has reported a positive result in an environment that has been extremely challenging," said GrainCorp Executive Chairman and Interim CEO Don Taylor.

Despite Australian wheat production during the 2013/14 season topping 27 million tonnes for the only the third time, production across New South Wales and Queensland suffered as hot, dry weather limited production.

Wheat production across Australia's east coast fell to a four-year low of 6.6 million tonnes, the Australian Bureau of Agriculture and Resource Economics and Sciences said.

And GrainCorp could be poised to endure further challenging conditions.

While wheat production during the current season has got of to a better start, buoyed by timely rains, the Australian Bureau of Meteorology has warned that the chance of an El Nino as early as July is about 70 percent.

The weather pattern, which can trigger droughts across Australia's east coast, could see significant curbs on production, especially if forecasts for a strong El Nino occur.

The last strong El Nino occurred in 1997 when wheat production fell to just 10.6 million tonnes.

($1 = 1.0671 Australian Dollars)

(Reporting by Colin Packham, Editing by Jane Wardell and Ed Davies)