LONDON -- The FTSE 100 (INDEX: ^FTSE) didn't really move today, hovering around 5,671 points by late afternoon -- just one point up on yesterday's close. The index of blue-chip shares was held back by a 4% fall in BP following further American accusations over the Deepwater Horizon disaster.

But individual constituents of the various FTSE indexes are having a good day, and here are three rising on good news.

Britvic (LSE: BVIC.L)
Britvic shares soared 13.6% to 373.2 pence this morning after the soft-drinks maker announced a merger attempt. A.G. Barr has apparently approached Britvic with a view to forming an all-share merger of the two companies, which would create one of Europe's major soft-drinks firms.

Current Britvic shareholders would own 63% of the merged company, with Barr shareholders holding the remaining 37%. Barr shares also reacted positively, gaining 3.8% to 431.5 pence.

Advanced Medical (LSE: AMS.L)
Wound care specialist Advanced Medical Solutions Group jumped 10% to 76 pence on the release of first-half results, which showed a 52% rise in revenue to 24.8 million pounds, with a whopping 98% rise in adjusted pre-tax profit to 5.4 million pounds. Fully diluted earnings came in at 1.87 pence per share -- 11% up, enabling a 17.2% boost to the interim dividend to 0.17 pence per share.

Chairman Dr. Don Evans said: "Further out, we have a number of exciting developments coming through our R&D pipeline which, combined with further strong progress anticipated in our existing businesses, lead the Board to be very optimistic about our long-term prospects."

Lansdowne Oil & Gas (LSE: LOGP.L)
Shares in Lansdowne Oil & Gas put on 4.4% to 58.5 pence this morning following further news on the Irish offshore Barryroe oil field, of which it owns 20%. Providence Resources holds the majority 80% but only saw a 1% rise to 632 pence.

A reappraisal of the field, which was first discovered back in the 1970s, has added a further 800 million to 1.2 billion barrels, in two new reservoir intervals, to the stocks already discovered.

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