Traders immediately welcomed the decision after the morning talks between authorities in Japan, the United States, the eurozone, Canada and Britain, with the yen sliding almost immediately against the dollar and European single unit.

And oil resumed its upward march after the United Nations agreed to air strikes on forces fighting for Libyan strongman Moamer Kadhafi as he wages an offensive against anti-government rebels.

In early European trade the US dollar was at 81.37 yen, compared with 78.95 in late US trade Thursday and the euro bought 114.35 yen from 110.67.

The Japanese unit soared to a post World War Two high 76.52 on Thursday as traders grew nervous about the situation at the nuclear plant as crews battled to avert a meltdown after it was rocked by last week's quake and tsunami.

The weakening yen boosted Japan's exporters Friday, sending the Nikkei stock index closing 2.72 percent, or 244.08 points, higher at 9,206.75.

Among the biggest gainers was TEPCO, the operator of the crippled plant, which closed 19 percent higher after losing around two-thirds of its value over the week.

However, the market was still more than 10 percent down over the week after diving 16 percent on Monday and Tuesday, its biggest two-day loss in 24 years.

News of the intervention had a knock-on effect for the rest of the region, with Sydney ending 1.56 percent, or 71.1 points, higher at 4,626.4 and Shanghai adding 0.33 percent, or 9.59 points, to end at 2,906.89.

Hong Kong edged up 15.80 points to 22,300.23 and Seoul ended 1.13 percent, or 22.10 points, higher at 1,981.13.

The Group of Seven said in a statement after the early morning talks in Tokyo: "We express our solidarity with the Japanese people in these difficult times, our readiness to provide any needed cooperation and our confidence in the resilience of the Japanese economy and financial sector.

"As we have long stated, excess volatility and disorderly movements in exchange rates have adverse implications for economic and financial stability. We will monitor exchange markets closely and will cooperate as appropriate."

Dealers said Japan stepped into the market to sell the yen soon after the statement while European central banks began their interventions later in the day.

The Bank of Japan on Friday injected another four trillion yen ($49 billion) of emergency funds into the short-term money markets -- the latest in a series of injections to prevent financial institutions running out of cash.

The central bank has now pumped a total of 38 trillion yen into the markets.

Global stocks have dived this week as the atomic crisis unfolds northeast of Tokyo, where authorities at the Fukushima No. 1 plant were trying to regain control after a series of blasts caused by the 9.0-magnitude quake and tsunami.

On oil markets crude jumped after the UN Security Council agreement to repel Kadhafi's forces in Libya.

The decision, which opens the way for imminent bombing raids, stoked worries about supplies from the oil-rich country, where anti-government forces are fighting to bring down the four-decade rule of strongman Kadhafi.

New York's main contract, light sweet crude for delivery in April, gained $1.65 to $103.07 per barrel while Brent North Sea crude for May was up $1.56 to $116.46.

Gold closed at $1,413.00-$1,414.00 an ounce in Hong Kong, up from Thursday's close of $1,396.20-$1,397.20.

In other markets:

-- Singapore fell 0.24 percent, or 7.10 points, to close at 2,935.78.

Hutchison Port Holdings Trust fell 5.94 percent to 95 US cents on its stock exchange debut.

Oil-rig maker Keppel Corp was down 0.70 percent to Sg$11.40 and auto distributor Jardine Cycle and Carriage lost 0.95 percent to Sg$33.42.

-- Taipei finished 1.35 percent, or 112.06 points, up at 8,394.75.

Taiwan Semiconductor Manufacturing Co was up 1.34 percent at Tw$68.3 while Chunghwa Telecom fell 0.23 percent to Tw$87.4.

-- Manila closed 0.33 percent, or 12.50 points, higher at 3,829.88.

Energy Development rose 1.9 percent to 6.29 pesos, Philippine Long Distance Telephone added 1.2 percent to 2,038 but Aboitiz Power was off 2.2 percent at 28.60.

-- Wellington rose 0.30 percent, or 9.92 points, to 3,339.51.

-- Kuala Lumpur ended 0.79 percent, or 9.85 points, higher at 1,503.89.

Palm oil giant IOI Corp gained 3.80 percent to 5.78 ringgit, state-owned power firm Tenaga Nasional rose 3.0 percent and gaming giant Genting Malaysia rose 3.0 percent to 3.40 ringgit but Telekom Malaysia fell 1.5 percent to 3.88

-- Jakarta rose 0.28 percent, or 9.85 points, to 3,494.07.

Coal producer Bumi Resources gained 3.3 percent to 3,100 rupiah and miner Indo Tambangraya Megah rose 4.0 percent to 48,200 rupiah.

-- Bangkok edged up 0.94 points to 1,003.29.

Banpu added 4.00 baht to 742.00, while Siam Cement gained 3.00 baht to close at 332.00.

-- Mumbai closed 1.49 percent, or 271.06 points, lower at 17,878.81.