* FTSE 100 index rises 0.4 percent
* Shire surges on report of new takeover bid
* St. James's Place gains on positive update
By Atul Prakash
LONDON, April 29 Britain's top share index climbed to a seven-week high on Tuesday, boosted by merger and acquisition news and positive updates from companies such as Whitbread and St. James's Place.
British drugmaker Shire jumped more than 3 percent, the biggest percentage gainer on the blue-chip FTSE 100 index , after Reuters reported that Botox-maker Allergan Inc was preparing a fresh takeover approach.
British wealth manager St. James's Place was up 2.1 percent after saying improved confidence among retail investors helped it get a strong start in 2014. Whitbread, the owner of Britain's Premier Inn hotel and Costa Coffee chains, rose 2 percent after posting a 16.5 percent rise in full-year profit.
"Investors are waiting to see the start of some positive earnings momentum, which has been missing in recent years. Any sign of a positive momentum is likely to support share prices," James Butterfill, global equity strategist at Coutts, said.
"We are also witnessing the biggest indicative M&A activities since the credit crisis, highlighting that corporate confidence is improving," he added. "A further rise in the GDP numbers would suggest that the economy is back on a stronger recovery path, confirming the strong PMI data."
Investors keenly awaited Britain's gross domestic product figures, due at 0830 GMT, which are likely to show that the country notched up its fastest economic growth in nearly four years in the first three months of 2014.
Bank of England Governor Mark Carney said in an interview published on Tuesday that Britain's economic recovery was starting to broaden and there were early signs it would be sustainable.
The FTSE index was up 0.4 percent at 6,726.22 points by 0758 GMT after hitting an intra-day high of 6,751.06 points, the highest level since early March.
Among other movers, oil major BP rose 0.9 percent after posting quarterly profit slightly above forecasts and raising its dividend for the second time in six months, in line with an earlier pledge to focus on returning more cash to shareholders. (Reporting by Atul Prakash; Editing by Andrew Heavens)