LONDON -- The FTSE 100 (INDEX: ^FTSE) slipped back in morning trading, falling 0.4% to 5,840 by midday, dragged down by mining shares. But it's only a small drop, and the index of top U.K. shares is still not far below its recent four-month high of 5,989 points.

But what individual constituents of the FTSE indexes are falling? We take a look at three that the FTSE should beat today.

FirstGroup (LSE: FGP.L)
FirstGroup fell 7.8% to 239 pence on the announcement that it has won the West Coast rail franchise from Virgin Trains. Why should such apparently good news cause the price to fall? Well, it's down to the staggering 5.5 billion pounds the company had to bid to gain control of the route for the next 14 years. The franchise is estimated to bring in revenue of around 900 million pounds a year, and there are fears that FirstGroup will not be able to run it profitably.

A suitably miffed Sir Richard Branson said: "We did not want to risk letting everybody down with almost certain bankruptcy at some time during the franchise, as happened to GNER and National Express who overbid on the East Coast mainline. Sadly, the government has chosen to take that risk with FirstGroup."

SuperGroup (LSE: SGP.L)
SuperGroup fell 1.8% to 428 pence on the announcement that co-founder Theo Karpathios, who owns 15% of the fashion firm, has resigned from the board with immediate effect. This comes a month after annual results showed a 15% fall in underlying pre-tax profits, which the company blamed on "largely self-inflicted" management failures.

The shares famously peaked at more than 18 pounds in early 2011 before falling from grace to slide all the way to 264 pence by June this year. But there's reasonable earnings growth expected for the next two years, putting the shares on a price-to-earnings ratio of 9.5, falling to around eight based on 2014 forecasts. The dividend is still low, however, at 1.5% to 2%.

Rio Tinto (LSE: RIO.L)
Actually, all the FTSE 100 miners are losing today, but with a drop of 4.4% to 3,050 pence at the time of writing, Rio Tinto leads the downward charge. Recent gains are turning a little sour, as renewed fears of falling demand for metals and minerals are sending the whole sector tumbling. Anglo American is down 3.2% to 1,954 pence, while BHP Billiton has fallen 2% to 1,944 pence.

But they're still looking cheap to me: Rio Tinto is on a forward P/E for this year of eight, falling to 6.8 next; Anglo American is at 10 and seven, respectively; and BHP Billiton is at 10 and nine. Buy cyclical shares when they're down? I've heard worse ideas.

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