Bloomberg FTSE fiasco
A blackout on Bloomberg computer terminals dragged the FTSE down on FridayGetty

The FTSE 100 slumped by almost 1% after a worldwide Bloomberg blackout was thought to have affected trading volumes.

The index of leading shares closed Friday at 6,994.63, down 65.82 points (-0.93%).

Bloomberg's trading and information terminals are used by approximately 320,000 people around the world and the two-hour outage is likely to have affected trading volumes.

The glitch meant the UK's Debt Management Office had to postpone an auction of short-term Treasury bills that was expected to raise £3bn ($4.48, €4.16bn).

"The modern way of getting a trade done is through Bloomberg chat, so without it, traders were a bit at a loss. Of course there is always a telephone if the deal is urgent," explained CMC Markets analyst Michael Hewson.

Bloomberg said in a statement: "Service has been fully restored. We experienced a combination of hardware and software failures in the network, which caused an excessive volume of network traffic.

"This led to customer disconnections as a result of the machines being overwhelmed. We discovered the root cause quickly, isolated the faulty hardware, and restarted the software.

"We are reviewing our multiple redundant systems, which failed to prevent this disruption."

FTSE 100 biggest risers

BP +5.90 (+1.25%) 479.35
Severn Trent +13.00 (+0.61%) 2,134.00
Sky +5.00 (+0.48%) 1,052.00
Whitbread +15.00 (+0.29%) 5,240.00
Barratt Developments +1.50 (+0.28%) 531.00

FTSE 100 biggest fallers

St James's Place -31.00 (-3.23%) 927.50
Anglo American -28.50 (-2.74%) 1,010.50
GKN -9.30 (-2.51%) 361.30
Schroders -83.00 (-2.48%) 3,259.00
Hargreaves Lansdown -28.00 (-2.26%) 1,209.00

The FTSE Aim 100 finished up a fraction on yesterday. The index closed at 3,408.22, up 0.34 (+0.01%) with the biggest riser healthcare technology firm hVIVO.

AIM biggest risers

hVIVO +48.50 (16.50%) 342.50
Velocys +17.25 (+13.72%) 143.00
CVS Group +23.00 (+3.85%) 620.00
GB Group +6.25 (+3.41%) 189.50
NewRiver Retail +10.00 (+3.36%) 308.00

AIM biggest fallers

Optimal Payments -212.75 (-42.13%) 292.25
Fusionex International
-25.00 (-6.94%) 335.00
Sirius Minerals
-0.75 (-5.26%) 13.50
Tungsten Corporation
-7.50 (-3.94%) 183.00
Jelf Group
-6.50 (-3.66%) 171.00