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.
UK blue chips saw their shares decline this morning following falls in the US and Asia overnight.
Wall Street has opened sharply lower this morning on the return of European sovereign debt fears.
The FTSE 100 fell 0.85% or 46.36 points to 5,392.83 this morning with Barclays among the biggest losers.
US stocks have opened sharply ahead this morning as private employers added more jobs than forecast in August, boosting optimism the world's largest economy can avoid slipping back into recession.
In the US, trading volumes fell ahead of key job market data to be released later today.
Speculation of M&A in various sectors, as well as rising precious and base metals miners, drove the FTSE upwards by 1.5% to 5,303.72 points by 2.15pm.
The FTSE 100 opened higher, up 0.25% or 12.95 points to 5,238.17, supported by encouraging economic data coming out of China this morning.