LONDON -- After a few volatile weeks, buffeted by eurozone panic and banking crises, the FTSE 100 (INDEX: ^FTSE) had a calm and smooth week, even as a number of British banks are being investigated for manipulating the inter-bank LIBOR rate.

From last week's close of 5,571 points, the index of top U.K. shares rose to a week's high of 5,725 on Thursday, before falling back a little to close Friday on 5,662, up 91 points, or 1.6%.

However, certain shares within the FTSE indices experienced a volatile week.

GKN (LSE: GKN.L)
GKN jumped 30.4 pence (17%) on the week to 211 pence, following the aviation engineer's announcement of a new deal to buy Volvo Aero, the aero engine division of AB Volvo, for a total consideration of 633 million pounds ($981 million).

The price of the takeover, which will be met partly by new debt and partly by a new equity issue, appears to have pleased the markets.

Quintain Estates & Development (LSE: QED.L)
Quintain Estates & Development jumped by 7.5 pence (20%) to 45.5 pence, after publishing further details of its new project with investor Knight Dragon, which is to invest cash in the development of the Greenwich peninsula in south London.

The partnership is 40% owned by Quintain, which is anticipating receiving cash of around 150 million pounds ($233 million) during the next six years, before any development profits.

Avocet Mining (LSE: AVM.L)
Avocet Mining collapsed by a further 27 pence (30%) to 63 pence, after plunging 61 pence (40%) the previous Friday to 90 pence.

The reason? Avocet's Inata gold mine in Burkina Faso is not going to meet its targets, because of a combination of operational and geological problems. The planned expansion of the mine is also going to be delayed, and it will not now commence before next year.

Production costs are expected to rise to $1,000 an ounce or more, and the firm is losing money on some of its hedged gold assets. Some are suggesting Avocet might be ripe for a takeover attempt.

Man Group (LSE: EMG.L)
Man Group slid a further 12.6 pence (17%) during the week to 63.7 pence, briefly hitting a new 52-week low of 61.1 pence on the way.

Confidence in the hedge fund manager's ability to turn around its performance -- especially that of its flagship AHL fund, which is not performing close to its high water marks -- has been steadily eroding and shows no sign of any reversal.

What now?
As usual, this week's FTSE trading provided some large share-price movements -- and perhaps some buying opportunities. Indeed, legendary investor Warren Buffett has spent more than $1 billion buying the shares of one of the U.K.'s most successful FTSE large caps.

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