Silchester International Investors, an independent fund manager set up by a former chief investment officer of Morgan Stanley, could hold the key to the success of Permira's £937m (€1.4bn) approach for WH Smith, the UK retailer.

WH Smith said on Monday that an indicative offer from Permira, the pan-European buy-out firm, valued the company at 375p a share - a 44% premium to WH Smith's closing price on Friday. Such an offer might not be enough to secure the support of Silchester, WH Smith's largest shareholder with a 16% holding largely when the retailer's share price was significantly higher at between 400p and 500p.