LONDON -- The FTSE 100 (INDEX: ^FTSE) continued its largely sideways movement this week, as sentiment was mixed between positive Chinese economic figures and uncertainties about the forthcoming FTSE interim reporting season.

After finishing last week on 5,662 points, the index of top U.K. shares dipped a little by Thursday, to recover and end the week just 4 points up, on 5,666 points.

But a number of companies listed in the FTSE indices had a considerably more volatile week.

Aegis Group (LSE: AGS.L)
Aegis Group jumped by 45% to 236 pence this week, after Japanese ad agency Dentsu made an agreed takeover bid for the FTSE-listed advertising and media group.

The offer of 240 pence per share, announced on Thursday, represents a premium of 48% on the previous day's close price, and the deal will create one of the world's largest advertising groups.

Britvic (LSE: BVIC)
Britvic shares slumped by 12.4% to 273 pence after the full details of a product recall became known. A new cap design on two of the soft drink maker's I products was defective, and the lines will now have to revert to an old design.

The recall, and the subsequent six months it will take to get back to full production capacity, is expected to knock 15 million to 25 million pounds ($23 million to $39 million) off pre-tax profit this year and next.

888 Holdings (LSE: 888.L)
Online gambling operator 888 Holdings saw its shares spike up 16.7% to 76 pence after upgrading its profit guidance for the year. The company's poker and casino offerings helped it to a strong second half of 2010, and that has extended into 2012, with full-year earnings now expected to be "materially ahead" of previous expectations.

The shares have rewarded investors nicely by doubling in the past 12 months.

FirstGroup (LSE: FGP.L)
Transport operator FirstGroup saw its shares trashed, down 11% to 190 pence, after fellow operator Stagecoach was forced to abandon its plans to buy one of FirstGroup's bus businesses in Devon for 2.8 million pounds ($4.3 million).

The cancellation, which coincides with the deal's being referred to the Competition Commission, has created fears that FirstGroup's planned 100 million pounds ($155 million) asset sale may now come under threat -- a fear that the company itself denied.

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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