More overseas companies are set to join London's leading index when the results of the latest FTSE reshuffle are announced today.
Indian oil and gas group Essar Energy is expected to make its debut in the FTSE 100 after its IPO last month raised £1.2 billion.
This saw it sell 23.2 per cent of the company at 420p a share in London's biggest flotation of the last two years.
Tanzania-focussed gold producer African Barrick Gold is also set for a spot in the top pack.
Its promotion could spell relegation for the London Stock Exchange and travel operator Thomas Cook.
Companies can join the FTSE 100 if they are among the top 90 UK-listed companies based on market capitalisation.
However, they can be pushed down to the FTSE 250 if they fall to position 111 or below.
Experts say the reshuffle, which will depend on share prices and liquidity levels at the close of play today (Wednesday), highlights the increasing internationalisation of the UK stock market.
Many FTSE 100-listed companies already have just a nominal presence in the UK.
These include South African brewer SABMiller, banking group Standard Chartered and mining giants Rio Tinto, BHP Billiton, Xstrata, Vedanta and Kazakhmys.
James Ferguson, capital markets partner at Deloitte, says: "There is clearly a trend developing, and we expect the pace of internationalisation to increase over the coming years.
"Having already seen two new companies come to market in the first six months of the year, we would not be surprised to see more coming over the next six months.
"There is a reputational kudos to having a primary listing in London and being part of a blue chip index. Similarly, there are certain sectors such as natural resources where London is the pre-eminent market.
"Companies are therefore attracted here, not just because of the perception that the UK has a less onerous regulatory environment, particularly in comparison with the US and the Sarbanes-Oxley Act, but also to be measured against their global peers, who also choose London."
While the top tier of the London Stock Exchange is increasingly becoming the preserve of the oil and gas titans, some of the smaller minnows are also set for promotion.
JD Sports fashion retailer could make the move up to the FTSE 250 after growing from a single store to a 500-strong chain in the last 30 years.
Its market cap currently stands at around £400 million which could be enough to lift it out of the FTSE Small Cap.