´óÏó´«Ã½

Ocado is joining the FTSE 100 after seeing a big jump in its share price following a year of dealmaking.

The online retailer's promotion to the blue-chip index was confirmed on Wednesday in the latest quarterly reshuffle.

Ocado is joined by betting firm GVC, owner of Ladbrokes Coral, while G4S and Mediclinic are demoted to the FTSE 250.

Marks & Spencer, in the FTSE 100 since the index was launched in 1984, just avoided the drop.

Ocado's elevation underlines a big transformation at the company, as well as the rapid growth of online retailing generally and its disruptive impact on firms like M&S.

The business has been selling its technology to international partners in France, Sweden and Canada, culminating in a transformational deal with US retailer Kroger earlier this month.

Hargreaves Lansdown senior analyst Laith Khalaf said Ocado had had "a sensational year" in which its share price trebled.

In 2012 Ocado's share price was languishing around 60p, amid speculation that it could breach its bank lending covenants. On Wednesday, the shares closed at 887.6p.

Ocado shares rocket 44% on US tech deal

M&S profits slump on store closure costs

Ocado's market cap value ballooned to £6.1bn, overtaking that of several FTSE 100 companies, including M&S.

Getting into the FTSE 100 can often fuel further demand for a company's shares, since funds that track the FTSE or invest in the index can then add that stock to their portfolios.

M&S narrowly avoided demotion. Its falling sales and share price are blamed on a failure to win back customers, as well as a poor online operation.

Mr Khalaf says the retailer's survival in the FTSE 100 may be "a stay of execution rather than a full pardon". M&S shares are down 5.5% this year.

Meanwhile, outsourcing firm G4S, which recently posted a fall in revenues, will be demoted to the FTSE 250, along with private hospital group Mediclinic International.

In other changes, Laird and Premier Oil are promoted to the FTSE 250. Marstons and Pets At Home are demoted.

Another FTSE 250 demotion is Woodford Patient Capital Trust, run by closely-watched investor Neil Woodford. The Trust's shares have fallen 13% this year.

Slipping even further were baby wear retailer Mothercare and fashion chain Moss Bros. They were relegated from the FTSE All-Share to the FTSE Fledgling index after their market value shrank.

Both have issued profit warnings this year, bruised by British shoppers' desertion of the High Street. Mothercare is in the throes of a restructuring.

Shares in Mothercare and Moss Bros are down 48% and 46% respectively since January.

The FTSE changes take effect after markets close on 15 June.