Oct 20 (Reuters) - The Slovak central bank's foreign currency reserves fell to $13.062 billion in the week to Oct 18, from $13.082 billion one week earlier, the bank said on Friday. SLOVAK FOREIGN RESERVES Oct 18 Oct 11 Oct 4 ($ million) Central Bank 13,061.5 13,081.8 13,230.1 Commercial banks 2,321.4 2,625.9 2,754.5 Total banking sector 15,382.9 15,707.7 15,984.6 NOTE: Reserves data are calculated according to methodology compatible with European Central Bank standards. (Reporting by Martin Santa in Bratislava) ((Editing by Gerrard Raven; editorial@reuters.sk; Reuters Messaging: martin.santa.reuters.com@reuters.net; +421 2 5341 8402)) Keywords: MARKETS SLOVAKIA RESERVES