The UK index of 100 leading shares was up in early trading, lifted by rises in all the major global markets.
A $3.7bn acquisition by consumer products giant Unilever led European markets higher in early Monday trade, the FTSE adding 0.2%.
Global stocks rallied on Friday on better eurozone news and stronger-than-expected manufacturing numbers in the US.
An increase in jobless claims in America exacerbated negative investor sentiment on Thursday, sending global stocks lower.
The Dow Jones has made early gains in trading as investors await the Fed's rate decision tomorrow and a possible extension of its quantitative easing programme.
A drop in consumer sentiment ruined a bright start on the Dow Jones in morning US trading on Friday, the index dropping into the red after an initial 0.35% spurt.
The FTSE 100 rose 0.88% or 48.58 points to 5,550.22 boosted by new financials regulation and positive economic data from China.
Banks and miners have powered the FTSE to a four-month high in afternoon trading after the Bank of England held interest rates at their historical lows.
The FTSE 100 has fallen 0.3% or 16 points to 5,413.5 in early trading after America's Federal Reserve said overnight there were "widespread signs of deceleration" in the US economy.
The FTSE 100 opened higher, up 0.47% or 25.67 points to 5,453.82, in response to Friday's better than expected US jobs data.