LONDON -- The FTSE 100 (INDEX: ^FTSE) has returned to business after the bank holiday weekend, rebounding 106 points, or 1.6%, by 8 a.m. EDT. Last week's fears of an end to economic stimulus seem to have faded, and the big FTSE 100 banks are all gaining today -- but things are still looking uncertain for the miners.

We have a few important bits of share price news today. Here are three companies from the various indexes whose shares are on the up.

AstraZeneca
AstraZeneca shares have had a good start to the day, gaining 3% after the pharmaceutical giant announced the acquisition of Omthera Pharmaceuticals. Omthera specializes in treatments for high blood lipids, and AstraZeneca will gain its investigational product Epanova, which may lead to treatment for very high triglyceride levels. A new drug application is expected this year.

The initial deal values Omthera shares at $12.70 apiece for an 88% premium on Friday's closing price and puts a total price tag on the company of approximately $323 million. There may also be extras for Omthera shareholders -- up to a further $120 million, depending on Epanova milestone targets.

Victrex
Shares in Victrex have picked up 6% after the polymer specialist announced a 15% boost to its interim dividend to 10.35 pence per share as it reported on its six months to March 31. Revenue for the group grew by a modest 0.8% to £106.4 million, with earnings per share up just 0.2% to 41.7 pence.

But the firm has a progressive dividend policy, and this boost to the first-half dividend comes after a 16% rise in last year's final dividend -- and it is pretty well covered by earnings. A similar rise in the final dividend this year would provide an overall annual yield of about 2.5%.

A.G. Barr (BAG 0.35%)
The A.G. Barr share price gained 2.5% to 584 pence in early trading, though it is back down to 574 pence at the time of writing. The soft-drink company, whose planned merger with Britvic was referred to the Competition Commission in February, released an AGM-day management statement today.

The firm's revenue for the 15 weeks to May 12 grew by 2.4%, which was ahead of a generally flat market, and Barr's core brands are said to be doing well. As for the merger, Barr expects to hear of provisional findings in early June and will reconsider the deal once those are available.

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