BRIEF-Taiwan's MediaTek posts September sales down 5.65 pct y/y

Oct 7 (Reuters) - MediaTek Inc * Says September sales at NT$18.55 billion (610.40 million US dollar), down 5.65 percent y/y Source text on Eikon: Further company coverage: (1 US dollar = 30.3900 Taiwan dollar) (Reporting by Hong Kong newsroom)