LONDON -- The FTSE 100 (INDEX: ^FTSE) is still depressed after yesterday's 100-point crash caused by reactions to U.S. markets. As of 10 a.m. EST the blue-chip index is up just 12 points to 5,803. Just when we were hoping it might head up further past the 5,900 level, it slumps below 5,800.

Some individual companies are having a bad day too. Here are three that are falling...

Balfour Beatty (LSE: BBY.L)
Shares in Balfour Beatty plunged 15% today to 260 pence after a profit warning. In a third-quarter update, the construction engineer told us of poor trading conditions in the construction business, with U.S. markets still depressed and performance in the U.K. lower than expected.

Full-year profit will be less than previously expected, though some of Balfour Beatty's divisions are having a better time of things and the company believes it is in a good position for the medium to long term. But the short-term outlook appears tough.

Dialight (LSE: DIA.L)
Dialight dropped 6.1% to 1,109 pence today, reversing a strong trend that had taken the shares up 60% in the past 12 months. The fall was caused by news of a contract delay for the LED lighting specialist, meaning that the firm's "Signal Lighting" division is performing below expectations, though growth is expected to return to normal in 2013.

With a highflying growth company like this, the slightest disappointment can cause a big drop, especially when the shares are so highly rated -- current forecasts put them on a forward price-to-earnings ratio of about 30 for the year to December.

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Howden Joinery (LSE: HWDN.L)
Howden Joinery, which had seen its shares soar by 60% since the start of the year, faltered today, dropping 3.3% to 160 pence. In its interim management statement, the firm told us things are generally going as expected and it is coping with demanding market conditions successfully.

The fall presumably comes down to general market sentiment, perhaps with a bit of profit-taking thrown in.

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