U.S. Stock index futures pointed to a mixed open on Wall Street on Tuesday, with futures for the S&P 500 down 0.2 percent, the Dow Jones futures down 0.1 percent and the Nasdaq 100 futures up 0.1 percent at 0740 GMT.

* The Federal Open Market Committee begins a two-day meeting on interest rate policy. The Fed is expected to try to push already low long-term interest rates even lower this week by tilting toward longer-duration bonds in its portfolio, a move known as Operation Twist.

* Samsung Electronics Co <005930.KS> is considering legal action to ban sales of Apple Inc's new iPhone, a source familiar with the matter said, in what could be its strongest step to defend against claims by Apple that the South Korean company had copied its product designs.

* ICSC/Goldman Sachs release chain store sales for the week ended Sept. 17 at 1145 GMT. In the previous week, sales rose 1.3 percent.

* Standard & Poor's cut its unsolicited ratings on Italy by one notch, a surprise move that sharply increases strains on the debt-stressed euro zone and piles pressure on policymakers to take more decisive action to resolve the crisis.

* International lenders told Greece on Monday it must shrink its public sector to avoid running out of money within weeks, as investors spooked by political setbacks in Europe dumped risky euro zone assets.

* Bank of China, a big market-maker in China's onshore foreign exchange market, has stopped foreign exchange forwards and swaps trading with several European banks due to the unfolding debt crisis in Europe, three sources with direct knowledge of the matter told Reuters on Tuesday.

* The U.S. Commerce Department releases housing starts and permits for August at 1230 GMT. Economists forecast a 590,000 annualized rate for starts versus 604,000 in July, and a total of 590,000 permits in August versus 601,000 in the prior month.

* Securities regulators have sent subpoenas to hedge funds and other trading firms as they probe possible insider trading before the U.S. government's long-term credit rating was cut last month, the Wall Street Journal said, citing people familiar with the matter.

* Major companies reporting results include Oracle, ConAgra Foods, Adobe and Carnival Corp .

* At 125 GMT, Redbook releases its Retail Sales Index of department and chain store sales for September versus August. In the prior period, sales rose 0.2 percent.

* U.S. trade officials will announce a major trade enforcement action against China on Tuesday, according to an advisory from the U.S. Trade Representative's office.

* U.S. reinsurer Transatlantic Holdings , which rejected a takeover offer from Warren Buffett's Berkshire Hathaway , is exploring a limited standstill agreement with Validus Holdings , the Wall Street Journal said, citing people familiar with the matter.

* President Barack Obama laid out a $3.6 trillion plan on Monday to cut U.S. budget deficits partly by raising taxes on the rich, but Republicans rejected it as a political stunt and made clear the proposal had little chance of becoming law.

* UBS AG Chief Executive Oswald Gruebel will seek a vote of confidence at a board meeting in Singapore for plans to slash the investment banking division that caused a $2.3 billion loss due to unauthorized trading, a Swiss newspaper reported.

* European shares turned positive in early trade as investors went bargain hunting following sharp falls in the previous session. The pan-European FTSEurofirst 300 <.FTEU3> index of top shares was up 0.4 percent. <.EU>

* Japan's Nikkei average <.N225> fell 1.6 percent after the market reopened following a holiday on Monday.

(Reporting by Atul Prakash; Editing by David Holmes)