I want to calculate company-level market cap values for stock exchanges listed by Bloomberg. I gather this can be calculated as the product of share price and the total of shares in circulation. But this approach does not seem to add up: for example the London Stock Exchange's data on FTSE100 members (see their 'List of All Companies') gives a £9,521.4 million cap value for Pearson, but calculating for this company from Bloomberg stats yields £2,796m (£1,331.00 * 2.1m shares).
Can anyone possibly clarify what the LSE figure is based on? I'm not an economist or finance expert but need reliable data on company cap values around the world. I'd prefer to get this centrally from somewhere like Bloomberg than interrogate 50+ exchange websites! So alternatively it would be really helpful to know of a better way to get this data.
Thanks in advance.