European stocks continued to rally in early trading Friday, mirroring a sharp surge on Wall Street Thursday amid buying spurred by the U.S. Federal Reserve's pledge to adopt a "patient" approach when raising interest rates in 2015.

The Stoxx Europe 600--having already closed the previous session almost 3% higher on the day--added another 0.6% shortly after the open as individual country indexes rose across Europe.

In the U.S., the Dow Jones Industrials on Thursday enjoyed their biggest two-day percentage gain in more than three years mainly fueled by the Fed's rhetoric, but also--traders said--by last-minute buying from hedge funds and other money managers whose performances have flagged this year.

Economists said that especially in Europe, confidence that the European Central Bank would announce a broadening of its asset purchase program to include sovereign bonds early next year, was buoying sentiment too.

In an interview with The Wall Street Journal earlier this week, ECB executive board member Benoît Coeuré sent one of the clearest signals to date that the ECB is poised to embark on large-scale asset purchases early next year, as the bank grapples with a weak economy and dangerously low inflation.

"The interview appears to make clear that it is not anymore a question of whether but how the ECB will buy sovereign bonds," Beat Siegenthaler, a currency strategist at UBS in Zurich said earlier this week.

Earlier in the session, data showed that German consumer sentiment has hit its highest level in eight years, on hopes economic expansion in Europe's largest economy will accelerate in the coming months.

In Russia on Friday, the ruble continued to recover from a brutal selloff earlier this week but remained volatile.

It eased to 62.9 against the dollar in the first few minutes of trading on the Moscow exchange but then recovered somewhat, edging close to its Thursday closing level of 61.4.

Earlier this week the Russian finance ministry said it was ready to sell as much as $7 billion to stabilize the ruble after the central bank carried out massive monetary tightening, hiking its key interest rate by 6.5 percentage points to 17%.

"The measures taken by Russian authorities to stem the ruble slide and contain the turmoil in Russian markets, coupled with perceptions of a dovish Fed, have sparked a turnaround over the past few trading sessions, " Barclays economists wrote. Nevertheless, the fate of the Russian economy is strongly linked to the price of oil.

On Friday Brent crude was trading close to $60 a barrel, having recovered somewhat from the 5 1/2 -year low of $58.50 hit earlier this week. Year-to-date, though, the price of the commodity has tumbled more than 45%.

Other currencies of economies dependent on oil, like the Canadian dollar and the Norwegian krone, were broadly unchanged on Friday. Nigeria's naira was also steady according to FactSet data, but remains close to an all-time low against the U.S. dollar, after the Nigerian central bank imposed new foreign-exchange controls on Wednesday. The bank barred dealers from depositing their currency-trading funds overnight, preventing them from placing bets for or against a single currency at the close of a trading session.

Finally Friday, the Bank of Japan announced that it is standing pat on monetary policy, opting to gauge the effects of its expanded stimulus campaign, despite a rapid fall in global oil prices that threatens its efforts to generate 2% inflation. That sent the U.S. dollar to one-week high against the yen of 119.47.

The buck was broadly steady against the euro at $1.2277.

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