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* St. James's Place, Barratt to join FTSE 100
* Tate & Lyle, Amec to slip to FTSE 250 index
* FTSE quarterly rebalance effective from March 24
By Atul Prakash
LONDON, March 5 (Reuters) - Wealth manager St. James's Place and housebuilder Barratt Developments will bepromoted to the blue-chip index of top British companies fromthe FTSE 250 index later this month, the FTSE Group saidon Wednesday.
The two firms, whose market capitalisation has surged aftera sharp share rally in the past months, will replace foodingredients company Tate & Lyle and engineering firmAmec in the FTSE 100 index. The changes will beeffective from March 24, the group said in a statement.
A promotion to the top index can fuel further demand for acompany's shares from funds that track the FTSE 100 or use it astheir benchmark, analysts said.
Newly independent St. James's Place, freed from thestrategic shackles of majority ownership by Lloyds BankingGroup, which sold out in late 2013, has impressed investors withits plans including the first acquisition.
That helped shares in the company, which manages money forwealthy individuals and families, rise 73 percent in 2013 andmore than 30 percent since the Dec. 13 disposal by Lloyds to alifetime high of 895.50 pence on Tuesday.
Around 9 percent of that performance has come since St.James's said on Feb. 25 that it planned to buy Asia-focusedHenley Group, an advisory business with around 400 millionpounds under management and 4,000 expatriate clients in HongKong, Singapore and Shanghai.
Riding the property boom, Barratt Developments,Britain's largest housebuilder by volume, has had a 27 percentshare price rise this year on the top of a 68 percent spike in2013, buoyed by the government's "Help to Buy" scheme launchedlast year to free up lending to home buyers.
Barratt said in January its total home sales grew 71 percentin the first six months of its financial year compared to theprior year, driven by a recovery in Britain's housing marketacross all regions.
British house prices are expected to rise 7 percent thisyear as a supply shortage and strong demand from overseasinvestors drive up the already-high prices of the Londonproperty market, a Reuters poll showed in February.
The elevation of St. James's Place and Barratt to the FTSEmeant that two other companies would leave to keep the total inthe benchmark index at 100. Tate & Lyle and Amec will be leaving due to their relatively weaker share performance.
Under the quarterly FTSE review, any company rising to 90thplace or above is automatically added to the FTSE 100 index,relegating the company at the bottom of the list to the mid-capFTSE 250 index.
Shares in Tate & Lyle slipped 21 percent this year to touchtheir lowest in more than two years on Monday. The company,which sells sucralose under the Splenda brand and otheringredients to packaged food and drink makers, recently cut itsprofit outlook partly due to competition from cheaper rivals inChina.
Amec, the other company that is leaving the FTSE 100 for theFTSE 250 index, has seen its shares gaining just 3 percent thisyear. The firm, which provides services and equipment for theoil and gas, mining, nuclear and renewable energy sectors, saidthis month it had been hit by weak prices and demand inBritain's power market.
Small cap companies Just Retirement Group, HeritageOil and Infinis Energy will find a place inthe FTSE 250 index, by knocking down Edinburgh Dragon Trust, Devro and Kenmare Resources to thesmall cap index.
