Crude price slide hits oil exporter currencies

Nigerian oil facility
Jacques Lhuillery | AFP | Getty Images

The Russian ruble isn't the only currency getting hit by the plunge in oil prices.

The slide in the ruble, which has lost nearly half its value since July, has raised concerns of a wider economic fallout if the drop continues. As oil prices have fallen, currencies of other developing countries that rely heavily on exports also have been sliding.

The list includes Nigeria, Angola and Algeria, which depend on hard currency from the sale of oil to finance government operations and pay for imported goods.

Read MorePutin speech sparks more ruble volatility

"The pressure on most of these currencies shows no signs of easing," Capital Economics economist Jack Allen said in a recent note to clients.

To be sure, part of the weakness in the currencies of oil producers comes as the dollar has strengthened, based on relatively strong U.S. economic growth prospects and strong investment inflows from around the world. Lower oil prices are expected to help boost U.S. growth because cheaper energy frees up cash for households to increase spending.

The outlook for the economies of oil exporters in the developing world depends heavily on where oil prices go from here. At week's end, crude prices appeared to be stabilizing, with the Brent benchmark holding at about $60 a barrel. After heavy selling pressure this week, the Russian currency also enjoyed a slight rebound as Russia's finance minister confirmed that the government had intervened to prop up its currency by using its foreign reserves to buy rubles.

Some oil exporters won't see the impact of lower crude prices on their currencies—because they don't let them float freely. Saudi Arabia, Oman, Venezuela, Qatar, and the United Arab Emirates are among those that fix the value in their currencies.

But fixing exchange rates won't isolate those countries from the impact of lower oil prices. Venezuela, for example, which relies heavily on oil sales for hard currency, has heavily devalued its official exchange rate and seen inflation skyrocket.

Read MoreIs the ruble undervalued yet?

In September, when the Venezuelan central bank stopped publishing the official inflation rate, prices were rising at an annual rate of 63 per cent.

Since then, prices have soared. In September 2013, Venezuelans were paying 125 bolivars for a Big Mac combo meal; by November 2014, the price had nearly doubled to 245 bolivars, according to Reuters.