Irish building materials firm CRH PLC (CRH) and two Russian companies--miner Evraz Group SA (EVRZ.LN) and gold and silver producer Polymetal International PLC (POLY.LN)--are expected to be promoted to the U.K.'s leading FTSE100 share index when the FTSE Group announces its quarterly review of stocks after the market closes Wednesday.

The three newcomers would replace satellite firm Inmarsat PLC (ISAT.LN), Anglo-African investment bank and wealth manager Investec PLC (INVP.LN) and primary platinum producer Lonmin PLC (LMI.LN).

The FTSE100 is a share index of the 100 most highly-capitalized companies listed on the London Stock Exchange.

Any company that falls to 111th and below is automatically ejected from the top-flight index, while any firm that rises to 90 or above is automatically promoted. Lonmin was ranked at number 109 based on Tuesday's closing share price and wouldn't usually be demoted, but for purposes of rebalancing will be considered when the committee meets later Wednesday.

Actual changes to the index will be based on Tuesday's closing prices, and entry to the index is effective at the close of trade on Dec. 16.

Investment funds that track the index will have to buy those stocks being promoted and sell those that are exiting, and these stocks are likely to become more widely traded as the date of index entry approaches.

At 1015 GMT, CRH shares were down 7 cents, or 0.5%, at 1397 cents; Evraz shares were down 3 pence, or 0.8%, at 395 pence, Polymetal shares were up 24 pence, or 2.4%, at 1039 pence; Inmarsat shares were up 4 pence, or 1.1%, at 431.1 pence, Investec shares were up 6 pence, or 1.8%, at 361.6 pence and Lonmin shares were up 27 pence, or 2.6%, at 1077 pence.

-By Ian Walker, Dow Jones Newswires; 44-20-7842-9296; ian.walker@dowjones.com