With the mining groups Billiton and Anglo-American, and South African Breweries already in the FTSE 100, the listing of the former mutual insurer, set to enter the blue-chip index in September, will add weight to the South African presence in the London market.
According to a recent note by the Salomon Smith Barney UK strategists Robert Buckland and Jonathan Stubbs, the South African Four will account for some 1.7 per cent of the London market. This is more than "proper" sectors such as property, tobacco and chemicals and almost as much as pubs and breweries.
These figures are even bigger if you include Liberty International, another insurerpart-owned by a South African parent.
Opening up the London bourse to emerging market companies is undoubtedly positive as it gives investors the chance to share in the enormous growth potential of those economies, and makes the City less of an old-school tie club. However, foreign firms can hide some nasty pitfalls, and investors - especially retail punters - should take extra care when venturing into little-known lands. In the case of the South African Four, the health warning comes in two shapes.
First, the four London-listed firms are also quoted on the Johannesburg stock exchange where they make up over 20 per cent of the index. This dominance means that the performance of the stocks is strongly correlated to the movements of a volatile bourse. Emerging equity markets tend to underperform more established exchanges in times of crisis and Johannesburg is no exception. During last year's global market malaise, for example, the index almost halved and fell to a five-year low.
The presence of a large proportion of South African investors can also reduce the supply of shares, making it difficult for tracker funds to achieve their weightings.
The second problem is to do with the economy. The vast majority of the earnings of the South African contingent comes from the home market and when you buy these shares you are effectively taking a punt on the local economy.
At present, South Africa is in rather bad shape with a recession-stricken economy, volatile interest rates and a depreciating currency. Although many experts believe that recovery is in sight, a cautious approach to South Africa-exposed stocks would not go amiss.
More domestically minded punters can focus on Kingston Communications this week.
Conditional dealings in the Hull-based telecom operator start today and investors are expected to give it a warm welcome. Analysts like the growth prospects of its Torch high-speed phone network and the steady stream of earnings of its fixed-line service.
This enthusiasm should push the final price towards the top of the 175p- 225p range, valuing Kingston at up to pounds 780m.
Freeserve, Dixons' Internet service provider, will send out its prospectus this week.
The document should shed some light on the mystery surrounding the company's valuation. Finger-in-the-air estimates range from pounds 500m to pounds 2bn and the market is hoping that Freeserve's huge band of advisers will come up with a more precise number.
This flotation excitement will make up for a very thin results schedule. Tomkins, the buns-to-guns conglomerate, will be guns-to-buns no more. The numbers will be overshadowed by embattled chairman Greg Hutchings' plans to do to revert Tomkins' legendary underperformance.
The group is expected to confirm long-awaited plans to demerge its bakery division Rank Hovis McDougall, which accounts for a third of profits.
Despite a pounds 350m-plus share buyback, the stock has trailed the market by around 24 per cent since late 1998. Mr Hutchings wants to spend its cash pile on acquisitions but has not yet found a suitable candidate and another share buyback is also likely.
Analysts are shooting for a minor drop in today's annual profits to pounds 493m from pounds 500m last time round. The dividend should increase by 1p to 14.7p. Tomkins' Smith & Wesson guns and Hovis bread divisions have held firm and should offset a poor performance by the US mowing equipment and bicycle business.
The Tomkins' upper echelons will also be seeking to lay to rest recent talks of a rift between Mr Hutchings and other board members.The remainder of the week will be taken up by a series of high-profile trading statements.
On the negative side, Marks & Spencer is expected to unveil an awful set of figures at its shareholder meeting on Thursday. Comparable sales in the past three months will be sharply down and some super bears are even talking of another profit warning.
Safeway's first quarter trading statement, expected tomorrow, will also be closely watched to take the pulse of the food retail sector.
On a happier note, the drinks giant Diageo should air a bullish assessment of current trading as the recovery in Asia and improving economic climate encourage consumers to feast on Guinness and other Diageo brands.