LONDON, Jan 18 (Reuters) - Accel Partners is leading a $20 million round of funding for Russian online shopping club kupiVIP.ru, which the company says is the largest investment to date in a Russian e-commerce vendor.

Venture capital firm Accel, known for backing firms such as Facebook and mobile ads specialist Admob, which Google (GOOG.O) is buying, will be joined by existing investors Mangrove Capital Partners, ARLAN, Direct Group and Oliver Jung.

KupiVIP sells discounted fashion goods from over 500 brands online. It launched in 2008 with an initial $11 million investment and has grown rapidly, with almost 1 million members joining in 2009.

"Russia has proven to be a vibrant market for the flash sales model, and we are very excited to partner with KupiVIP, the fast-growing category leader in the region," said Accel's Sonali De Rycker, who will join KupiVIP's board. (Reporting by Georgina Prodhan, editing by Will Waterman)