LONDON (AFX) - The dollar gained further ground against the yen in midday trade after the European Central Bank confirmed that it had intervened once again on behalf of the Bank of Japan to prevent the yen4s appreciation, dealers said. The dollar has also been supported by the stock market recovery this week and hopes that the slide in the oil price will contribute to an early bounce back from recession. The ECB said it had bought euros against the yen as part of an agency agreement between the ECB and the BOJ which has existed for over a year. The BoJ is anxious to halt the yen4s appreciation against the dollar, and has intervened on five separate days over the last ten. The ECB performed a similar action for the BoJ on Monday. Steve Barrow, currency strategist at Bear Stearns, now expects the dollar to continue to appreciate against the yen. "It appears that the BoJ has worn out the dollar bears," he said. "$-yen could be driven up to 120, that4s more likely than it going down to 115." Michael Klawitter, strategist at WestLB, agrees and thinks that the need for the BoJ to intervene will decline over the next couple of weeks, as Japan4s fiscal half year ends. Capital repatriation should slow down and capital outflows should recommence, he said. "I think that in the next half year, we will see further yen weakness," he said. In the meantime, the BoJ is likely to continue to act on its own, with some support from the ECB, said Bear Stearn4s Barrow. Talk that the US Federal Reserve may be asked to get involved is unlikely, he said. "The BoJ would be loathe to bring in the Fed, which is burdened with massive problems of its own," he said. Other key developments today include the continued depreciation of the swiss franc, particularly against the euro. The markets were surprised by the SNB4s move earlier this week and investors are "unwinding their over-bought positions", said Barrow. On Monday the Swiss National Bank surprised the markets when it cut its 3-month-Libor target range by 50 basis points to 1.75-2.75 pct. This was its second reduction in a week. However, both Barrow and Klawitter think a strike against Afghanistan will encourage flight back into the Swiss franc. Meanwhile sterling is up against the dollar for the third day running though trading has been light. Some dealers said growth forecasts later from the International Monetary Fund should show the UK in comparatively good light. "They will show that the UK is not as big a basket case as others," said one.