Coffee prices rose on Thursday, as the US dollar held against most currencies, amid renewed concerns over the Brazilian supply.

The Brazilian Public Food Commissariat reported that there were frost waves that affected 150,000 to 200,000 hectares, or about 11% of the country's coffee-grown areas in the country.

Coffee traders said that this is the first time since 1994 that Brazil has experienced such bad weather, which foreshadows several other upcoming frost waves.

The total traded coffee options contracts during July were at a record of 664,648.

The dollar index fell against a basket of major currencies by less than 0.1% to 92.9 points as of 13:24 GMT, after hitting a high of 93.01 points and a low of 92.8 points.

As of 13:30 GMT, coffee spot prices rose 0.6% to $1.85 a pound.