LONDON, April 12 (Reuters) - Arabica coffee futures on ICE rallied by about 5% on Friday to their highest in 18 months on worries over adverse weather in top producer Brazil and tightening supplies in leading robusta grower Vietnam.

Robusta futures hit their highest in at least 16 years while the relentless rally in cocoa continued, with New York futures again hitting record highs above $10,000 per metric ton.

COFFEE

* July arabica coffee rose 4.8% to $2.2800 per lb by 1308 GMT after touching an 18-month high of $2.2925.

* Arabica prices have benefited from a sustained robusta price rally this year, which has prompted roasters to boost the amount of arabica coffee they use in blends and reduce robusta volumes.

* "Concerns surrounding supply in (top robusta producer) Vietnam and below-average rainfall in Minas Gerais, a Brazilian region which produces around 30% of the countrys arabica crop, have contributed to the tightening of the market," Fitch Solutions said in a note.

* Brazil is by far the world's largest arabica producer.

* July robusta coffee rose 2.2% to $3,872 a ton. It earlier hit $3,893 for the highest level since the contract started trading in 2008.

* There are deepening concerns about the crop outlook in Vietnam because of dry conditions, with dealers saying that farmers remain reluctant to sell as they grow increasingly confident of even higher prices.

COCOA

* July London cocoa rose 2.1% to 8,389 pounds per metric ton after hitting a record high of 8,474 pounds.

* Top producers Ivory Coast and Ghana are in the midst of one of their worst harvests.

* ICE-monitored cocoa inventories in U.S. ports are at their lowest in three years.

* July New York cocoa was up 2.6% at $10,150 a ton after touching a record peak of $10,243.

SUGAR

* May raw sugar settled 0.61 cent, or 2.8%, down at 20.85 cents per lb after slumping to a one-month low of 20.81 cents.

* Brazilian industry group UNICA will release production data for that second half of March at 1500 GMT on Friday.

* May white sugar lost 0.7% to $628.10 a ton. (Reporting by Maytaal Angel Editing by David Goodman)