Russia devalues the rouble again

Russia has been devaluing its currency gradually

Russia has devalued its currency, the rouble, for the third time this week and the seventh time this month.

It takes it to its lowest value against the US dollar since January 2006.

The Russian currency has been hit by the price of oil, which is Russia's main export. Oil prices are more than $100 a barrel below their July peak.

The rouble is now more than 15% below its record levels against the US dollar, which were set at the beginning of August.

Russia's central bank has spent more than $100bn (£68bn) defending its currency since the summer.

It has opted to devalue gradually by widening the rouble's trading band, instead of making a single big devaluation.

"All the commodity currencies have devalued and the rouble is a laggard here," said Alexei Moisseev at Renaissance Capital.

"Judging by the pace they are moving at, they could do two more moves before the end of the year."

"When you are going at such pace, there is a real chance it will help, it is a real alternative to a [big] one-off devaluation."