* FTSEurofirst 300 flat as investors eye central banks
* New CEO choice boosts Unilever; BP gains on Russia move
* Commodities track oils, metals higher
By Sitaraman Shankar
LONDON, Sept 4 (Reuters) - European shares traded flat early on Thursday as investors stayed edgy ahead of key central bank rate decisions, negating the effect of a surge in commodity stocks and in Unilever <ULVR.L> on its choice of chief executive.
At 0821 GMT, the FTSEurofirst 300 <
> index of top European shares was flat at 1,181.53 points, as weaker banks offset firmer commodity and food stocks.HSBC <HSBA.L> fell 1.6 percent and Commerzbank <CBKG.DE> lost 0.8 percent.
Unilever jumped 6 percent to top percentage gainers across Europe after it announced the appointment of Nestle <NESN.VX> executive Paul Polman as its new head.
Shares in BP <BP.L> were the top weighted gainer, rising 4 percent after a source said that it was close to a deal to settle a dispute over a Russian joint venture. BP later said a memorandum of understanding on the issue had been signed.
Later in the day, investors will train their focus squarely on interest rate decisions from the Bank of England at 1100 GMT and the European Central Bank at 1145 GMT.
Both central banks are expected to stay on hold, but the ECB may shake up collateral rules, putting a stop to banks swapping complex, untraded and near impossible-to-value assets for ECB funds.
"We're not expecting a great deal from the central banks today -- the ECB will stress the fact that inflation remains high," said Thierry Lacraz, strategist at Swiss bank Pictet.
"After the Australian central bank cut rates, we would expect the English to follow, likely later this year, and the ECB to cut at the beginning of next year."
"The next move of the Fed could be an increase -- they're not part of the same cycle as the others," he said.
Sweden's central bank raised its key interest rate by a quarter percentage point to 4.75 percent, focusing on above-target inflation rather than slowing economic growth.
Across Europe, Britain's FTSE <
> was up 0.5 percent, while Germany's DAX < > fell 0.6 percent and France's CAC < > lost 0.4 percent.
COMMODITIES SURGE
Heavyweight oils and mining stocks were broadly stronger as crude <CLc1> ticked 43 cents higher to $109.78 a barrel, gold bounced and copper futures rose.
Antofagasta <ANTO.L> gained 2.9 percent and Kazakhmys <KAZ.L> rose 2.5 percent, while Total <TOTF.PA> rose 2 percent and Shell <RDSa.L> gained 1 percent.
Technology stocks weakened as investors fretted that an economic slowdown would hurt tech spending. Nokia <NOK1V.HE> fell 1.7 percent and STMicro <STM.PA> lost 2.1 percent.
French bank Natixis <CNAT.PA> was a standout gainer, jumping 7 percent as analysts bet on the success of its deeply discounted rights issue.
Pictet's Lacraz said that he expected stocks to remain weak.
"September and October are traditionally not very good -- and we are entering the bank announcements season," he said.
Traders said investors were unlikely to make bets either way before the central bank decisions.
"We expect Trichet to come out with strong language suggesting Europe is in recession -- if you were a fund manager sitting on 2 or 3 billion euros, would you be out there buying ahead of such comments?" said a trader, referring to weakness in bank stocks. (Editing by Quentin Bryar)