By Roberto SamoraSAO PAULO, Sept 17 (Reuters) - Brazil's beef exports to the United States are seen falling further in September from the previous months, the head of local beef lobby Abiec said on Wednesday, in a move linked to higher tariffs imposed by President Donald Trump on goods from Brazil. Roberto Perosa said that beef exports to the U.S. should fall to about 7,000 metric tons in September, from around 9,000 tons in August and 30,000 tons per month in the period preceding the tariffs, which came into force in August. Why It's ImportantThe U.S. used to be the second-largest buyer of beef from Brazil, the world's largest exporter, only behind China. The fresh duties added to a 26.4% import tax faced by Brazilian beef that was shipped outside a previously established quota. "But surprisingly, even with the 76.4% tariff, there are still exports to the U.S. because of the competitiveness we have gained."