* Latest strikes impact markets, concern investors
* Worry Zuma cannot satisfy investors and powerbase
* Even if strikes short lived, impact will linger
By Peter Apps, Political Risk Correspondent
LONDON, Aug 5 (Reuters) - Having shrugged off South African strikes and unrest last week, foreign investors are becoming more alarmed as they continue worrying President Jacob Zuma may no longer be able to satisfy both them and a populist powerbase.
South Africa's biggest union said on Wednesday its members would strike at power firm Eskom, threatening mine production, prompting platinum and palladium prices to spike higher and blamed for undermining the rand currency.
Zuma went to great lengths to reassure foreign investors both before and after his election earlier this year that he would not move the country to the left, but with the economic crisis worsening he has come under mounting pressure.
"Zuma has said one thing to foreign investors to keep them happy and another to his union and Communist allies," said analyst Mats Oluasson at Swedish bank SEB. "It is obviously becoming more difficult for him to do that. South Africa looks like it will underperform other emerging markets, both for political and economic reasons."
Fifteen years after the end of apartheid, many South Africans still live in poor townships and are becoming increasingly frustrated. Zuma has said he will offer them change, but finances were tight even before the economic crisis.
A possible Eskom strike follows a week-long council workers strike that disrupted public services before workers settled for a wage increase of almost double the inflation rate of 6.9 percent annually.
Markets had largely ignored that, as well as sporadic unrest last week in townships over unemployment and poor services. But a string of new strikes and threats from telecoms and textile workers -- and now at Eskom -- have changed that.
NEGATIVE HEADLINES
"You have had a sustained flow of headlines," said Royal Bank of Canada emerging foreign exchange strategist Nigel Rendell. "It has hit sentiment towards the rand so it has missed out on a broader emerging markets rally. It is too soon to say it is a real turning point in sentiment towards South Africa."
Brokers in Johannesburg said they believed recent rand moves were more down to economics than politics.
Analysts say it could have been worse -- several other union groups reached wage deals including in the key mining sector without striking.
While the Johannesburg stock market shrugged off the new strikes, up more than 1 percent on Wednesday on higher commodity prices, the rand sank 1.94 percent by 1345 GMT, the worst performer by far amongst emerging currencies.
SEB said it was recommending selling the rand to buy Turkish lira, partly on political worries as well as fears South Africa would be slower than other countries to emerge from recession.
Analysts fear the above-inflation wage deals will drive inflation and undermine balance sheets -- and that the strikes themselves will further dent faltering economic output.
"Obviously, a shorter strike would be better for markets but there may still be a lasting impact," said Oluasson. "The wage deals we are seeing are not as bad as they could be for the economy but they could certainly be better."
While unions around the world have gained a louder voice since the beginning of the economic crisis, South Africa is one of the first countries to see genuine widespread labour disputes, perhaps because of its relatively stronger unions.
For a factbox on trade union activity in the Middle East and Africa, click here
For a factbox on the unions in emerging Europe, click here
For a factbox on unions in Western Europe, click here