(Adds data, quote, table) By Dion Rabouin Oct 6 (Reuters) - Speculators cut their bearish bets on the U.S. dollar from the previous week, which showed the highest level in net-short contracts in five years, but held their negative bias for the U.S. currency. The value of the dollar's net short position was $16.83 billion in the week ended Oct. 3, leaving investors net short on the greenback for the 12th straight week, according to data from the Commodity Futures Trading Commission released Friday. Net short bets on the dollar had grown to $17.36 billion for the week ended Sept. 26, the highest since late September 2012. In a wider measure of dollar positioning that includes net contracts on the New Zealand dollar, Mexican peso, Brazilian real and Russian ruble, the U.S. dollar posted a net short position valued at $21.01 billion, down slightly from $21.13 billion a week earlier. The dollar had its best week of the year against a gauge of six rival currencies last week after more hawkish signals from the Federal Reserve during its monetary policy meeting, which raised prospects for an increase of U.S. interest rates by year-end. A larger move could come next week in Europe as Spain wrestles with an independence vote from Catalonia. Carles Puigdemont, Catalonia’s separatist leader, is set to appear before lawmakers on Tuesday. "Although it’s calmed down in the past day or two, the big event that’s going on right now is put on hold until debate (next week)," said Joseph Trevisani, chief market strategist at WorldWide Markets in Woodcliff Lake, New Jersey. "The currency markets are telling you that they’re not going to (secede). If everyone was convinced they were going to do it, euro would be at $1.12." The euro closed Tuesday at $1.1742 and was last at $1.1731 on Friday. The Reuters calculation for the aggregate U.S. dollar position is derived from net positions of International Monetary speculators in the yen, euro, British pound, Swiss franc and Canadian and Australian dollars. Japanese Yen (Contracts of 12,500,000 yen) $7.947 billion 03 Oct 2017 Prior week week Long 58,770 42,963 Short 143,413 114,310 Net -84,643 -71,347 EURO (Contracts of 125,000 euros) $-12.995 billion 03 Oct 2017 Prior week week Long 187,053 183,679 Short 96,220 95,512 Net 90,833 88,167 POUND STERLING (Contracts of 62,500 pounds sterling) $-0.425 billion 03 Oct 2017 Prior week week Long 80,325 80,145 Short 60,376 75,091 Net 19,949 5,054 SWISS FRANC (Contracts of 125,000 Swiss francs) $0.24 billion 03 Oct 2017 Prior week week Long 17,614 14,926 Short 20,907 16,788 Net -3,293 -1,862 CANADIAN DOLLAR (Contracts of 100,000 Canadian dollars) $-6.043 billion 03 Oct 2017 Prior week week Long 97,204 102,688 Short 22,076 28,083 Net 75,128 74,605 AUSTRALIAN DOLLAR (Contracts of 100,000 Aussie dollars) $-6.088 billion 03 Oct 2017 Prior week week Long 98,499 103,507 Short 26,687 26,313 Net 71,812 77,194 MEXICAN PESO (Contracts of 500,000 pesos) $-2.332 billion 03 Oct 2017 Prior week week Long 117,452 134,621 Short 28,336 50,894 Net 89,116 83,727 NEW ZEALAND DOLLAR (Contracts of 100,000 New Zealand dollars) $-0.58 billion 03 Oct 2017 Prior week week Long 20,928 22,369 Short 12,810 14,316 Net 8,118 8,053 (Reporting by Dion Rabouin in New York; Editing by Lisa Shumaker)