(Reuters) - Australian production of wine grapes is set to sink to a five-year low this year after two wet summers damaged vines in New South Wales and South Australia, data on Wednesday showed. Production in the 2011/12 season will total about 1.53 million tonnes, down 2 percent on last year, the Australian Bureau of Agricultural and Resource Economics and Sciences (ABARES) said. Australian wine exports have waned in recent years after its bold and brassy reds in particular first took the world by storm, while global competition from newer suppliers including South Africa and Chile has seen an increase in the proportion of Australian wine shipped in bulk.