Opinion was mixed, however, over the future direction of the FTSE 100, which has gained about 8 percent in the year to date but is down about 6 percent from a four-year high on Oct. 3 as inflation and interest rate worries have combined to knock global equity markets.
The FTSE 100 index of blue chip shares closed 30.6 points, or 0.6 percent, higher at 5,213.4 points - a 70-point gain for the week.
"We have had a year so far where both the FTSE and the European markets have posted strong gains," said Jim Wood-Smith, head of research at brokers Christows. "It is difficult to see how much longer that is going to go on for.
"If we finish the year at 5,200, it will be a very good outcome," he added.
Since the FTSE's tumble, some analysts have shaved year-end forecasts, and others see the FTSE falling further.
"We think we have started a small correction," said Eric Lanteigne, a technical analyst at Collins Stewart, who sees the FTSE struggling to break above 5,400 in the short term. "It was a little odd when we broke 5,400; it proved to be a false move."
But others see further gains in the market, citing a generally positive tone to third-quarter earnings, relatively cheap stock valuations and mergers and acquisitions activity as providing additional support to share prices.
"There is plenty of reason to be positive about the UK stock market," said Neil Parker, a market strategist at Royal Bank of Scotland. "We may have priced out a rate cut in the UK a bit too easily."
Driving much of Friday's surge was GlaxoSmithKline, rising 2.5 percent and adding more than 8 points to FTSE gains. The firm said it had inadvertently published an internal estimate showing 2005 earnings growing at the top of its newly increased forecast range.
Dealers also reported that investors switched into the stock from rival AstraZeneca after Swiss investment bank UBS upgraded its rating on Glaxo and downgraded Astra, which fell 0.6 percent.
Smith & Nephew rose 3.8 percent after positive comments from analysts following its third-quarter results on Thursday.
Telecoms stocks bolstered the index with BT, rumoured bid target O2, Vodafone and Cable & Wireless all posting gains.
Vodafone returned to India with a $1.5 billion deal to buy 10 percent of the country's top mobile phone firm, Bharti Tele-Ventures, while traders said bid rumours helped to attract buyers to O2 and C&W.
"The buyers are always there for O2," one dealer said. "There is no smoke without fire."
Long-rumoured bid target and utility Centrica also rose, closing 2.6 percent higher.
On the downside, mining stocks were weaker as dealers pointed to concerns over US GDP data, which showed solid economic growth and fuelled fears that interest rates would have to rise quicker than many predict in the US, which could hurt demand for natural resources.
Anglo American shed 1.5 percent, while Xstrata lost 1 percent.
Mid-cap food maker RHM shed 8.6 percent to fall below its July debut price after it said cake sales had slumped in the first half.