Nov 1 (Reuters) - Multiple funds managed by Blackrock (BLK.N) are selling about 55 million shares in British e-commerce group THG (THG.L), a bookrunner said on Monday. Blackrock is the biggest institutional shareholder of THG after the company founder Matthew Moulding"s 14.19% holding, according to Refinitiv Eikon. THG was rocked by a 35% share price collapse after an underwhelming investor presentation in October, forcing it to address corporate governance concerns more broadly. read more The company has tried to allay investor concerns, but so far has had little traction in halting the fall in its share price.THG appointed an executive from backer SoftBank (9984.T) to its board of directors last month and said it was looking for an independent chair ahead of a proposed premium listing on the London Stock Exchange. read more Shares of THG have fallen nearly 66% since the start of September. ($1 = 0.7320 pounds)