The last-minute drop in the share price left BA as the 111th biggest company in the London stock market, valued at £1.461bn, just £4m below the 110th ranked company, the technology group Arm Holdings. Under the FTSE 100 rules, any company ranked below 110 at the time of the quarterly shake-up is automatically thrown out of the index of top companies. The relegation will be officially confirmed later today. Two other companies, music giant EMI and electricity generator International Power, are also certain to be kicked out.