Drug company Hikma Pharmaceuticals PLC (LON:HIK) ascended to the FTSE 100 Index as the decline of oil and mining in London's top flight continued.
Hikma is set to enter the FTSE 100 in the latest quarterly review of the index at the expense of satellite group Inmarsat (LON:ISAT), which drops to the FTSE 250 Index.
City firm AJ Bell said Hikma’s promotion and Inmarsat’s demotion showed the fluidity of the Footsie.
Since the launch of the index in 1984, there have been over 400 changes to the benchmark's membership.
Oil, banking and mining stocks have decreased in influence in the last 10 years, with tobacco, drinks, travel & leisure and support services taking up the slack.
Mining stocks faced the third biggest decline in their position in the FTSE 100, falling from 7.1% in 2006 to just 4.7% today.
Oil was second with a decline to 13% from 19.3% and banking had the biggest setback, dropping to 11.1% from 20.8%.
Bell’s investment director Russ Mould said: “The most dramatic changes to the index tend to occur when a sector is hot or conversely is falling from grace.
“These trends can lead to a rash of promotions or demotions, trends which can make or cost investors money if they are (or are not) spotted soon enough.
“The biggest slump over the past ten years has been seen in the banking sector following the financial crisis of 2008 and a host of mis-selling scandals.
“Resource sectors have also seen huge change since 2006. The collapse of the oil price and BP’s (LON:BP.) Deepwater Horizon disaster have seen the presence of oil stocks in the FTSE 100 fall from 19.3% in 2006 to 13% today.
“Slowing demand for commodities from emerging markets and the resulting collapse in prices have also hit mining stocks hard."
But Mould added that oil and banking stocks remain the two largest sectors in the FTSE 100 and were still of huge importance to its future performance.
Entering the second tier are Ascential PLC (LON:ASCL), CMC Markets Plc (LON:CMCX), Countryside Properties PLC (LON:CSP), CYBG PLC (LON:CYBG), Hill & Smith Holdings PLC (LON:HILS), Metro Bank PLC (LON:MTRO) and Smurfit Kappa Group Ltd (LON:SKG).
Ophir Energy Plc (LON:OPHR) dropped from the FTSE 250 Index after its shares fell from 132p in June last year to 71.35p on Thursday.
Joining Ophir in exiting are Highbridge Multi-Strategy Fund Ltd (LON:HMSF), Interserve PLC (LON:IRV), Jimmy Choo PLC (LON:CHOO), Lookers PLC (LON:LOOK), Melrose Industries PLC (LON:MRO), Northgate PLC (LON:NTG).
CMC enters the second tier after making its market debut in February. Its shares will now trade in the same index as rival IG Group Holdings PLC (LON:IGG) and attract a wave of passive tracker money.