United Utilities finished the day as the FTSE 100’s best performer this afternoon, following news of the sale of a subsidiary business.

The company has confirmed it will be selling its 50 per cent holding in electricity and gas metering company Meter Fit to its business associate Marlin.

United is set for a windfall of £24 million from the deal with Marlin shouldering the burden of £95 million in debt.

The company’s share price rose 4.4 per cent to 585 pence on the news, ahead of Severn Trent which gained 2.8 per cent to 1,316 pence.

British Airways completed the top three line up today after the company reported improved operational performance from cost savings in its interim results.

Investors responded after the company confirmed an agreement with the Pensions Regulator over its troubled pensions scheme and news of the merger with Iberia.

The firm announced an operating loss of £71 million for the three months to 30 June, £20 million lower than the same period in 2009. Its share price rose 1.8 per cent to 219 pence.

Essar Energy was the day’s worst performer, slipping 3.7 per cent to 413.1 pence ahead of MAN Group, down 2.4 per cent at 218 pence and Segro which lost another 2.4 per cent at 280.3 pence.