* FTSEurofirst 300 index gains 1 percent
* ARM Holdings rises as bid talk resurfaces
* National Bank of Greece cash call hits shares
By Joanne Frearson
LONDON, Sept 8 (Reuters) - European shares rose on Wednesday, with a key index making its highest close in four months, boosted by technology stocks as ARM Holdings jumped on renewed bid talks and as miners also gained.
ARM Holdings jumped 5.8 percent, with traders citing bid rumours, while RBS repeated its "buy" rating on the firm after Samsung selected Arm's technology for its new mobile phone chip.
The FTSEurofirst 300 index of top European shares closed 1 percent higher at 1,072 points, its highest close since 26 April, after being as low as 1,057.35.
Stocks also benefited from Portugal's successful raising of 1.04 billion euros ($1.32 billion) in the debt market. But Lisbon had to pay higher yields compared with previous sales, underscoring the challenging environment for peripheral euro zone issuers. "The Portuguese debt well was perceived well and has helped the market," said Philippe Gijsels, head of research at BNP Paribas Fortis Global Markets in Brussels.
"But, there is still uncertainty about the global economies and the markets are reacting positively or negatively to minor news as they can't get the answer to the bigger questions. The market is within a trading range and there are wild intraday swings."
Portugal's PSI 20 index fell 0.8, while Ireland's ISEQ slipped 0.9 percent.
Ireland's government outlined a compromise solution for winding down troubled Anglo Irish Bank but failed to put either a price or a timeline on its plan. Bank of Ireland and Allied Irish Bank slipped 3.9 percent and 0.8 percent, respectively.
NATIONAL BANK OF GREECE FALLS
The National Bank of Greece fell 6.4 percent after it said it is to raise 2.8 billion euros ($3.6 billion) via a rights issue, a convertible bond, and the sale of a stake in its profitable Turkish unit, to deal with the debt crisis.
However, the STOXX Europe 600 Banks was up 0.4 percent, reversing earlier losses.
Investors are waiting for details of new rules by the Basel Committee that will determine how much capital banks will have to set aside as a safety net, with details expected on Sunday.
"Worries about the stability of the banking system have not gone away and until there is more clarity (on new capital requirement rules for the banks), investors look to be more comfortable sitting on the sidelines," a London-based trader said.
Miners were also in demand as a weaker dollar made industrial metals cheaper for non-U.S. currency holders. Anglo American, Antofagasta and Xstrata rose 1.6 to 3.1 percent.
The Euro STOXX 50, the euro zone's blue-chip index, gained 0.9 percent to 2,752.89 points, above the 50 percent Fibonacci retracement of a fall to a low in May from a high in April. Analysts said the index was range-bound between 2,500 and 2,800.
Across Europe, the FTSE 100 index was 0.4 percent higher, Germany's DAX was up 0.8 percent and France's CAC 40 gained 0.9 percent. (Reporting by Joanne Frearson; Editing by Erica Billingham)