A company report accessed online is referenced in the same way as a webpage. Most courses use Harvard style from Cite Them Right, which we’ve used to generate the following example reference:
In-text citation:
(Sky plc, 2016)
Reference list:
Sky plc (2016) Annual report 2016. Available at: https://corporate.sky.com/documents/annual-report-2016/annual-report-2016-singles.pdf (Accessed: 7 December 2016).