Housebuilder Berkeley Group could make a grand entrance to the FTSE 100 later this month, while engineering business Weir Group is set for a demotion into the FTSE 250 as part of the index's quarterly review.
The move is based on the companies' position within their current respective indices. The FTSE EMEA Committee will now decide who is up and who is down during its review on 2 September, using close of play data from today.
Any changes will take place after market close on 18 September.
Berkeley's share price has soared over the past year, while Weir Group has steadily fallen.
There are also a number of small caps that could be breaking into the FTSE 250 index. Sophos Group, Circassia Pharmaceuticals and P2P Global Investments could join the index, while Premier Farnell and Lonmin could be ejected. Fisher (James) & Sons may also be on the list of companies being demoted.