Stock futures pointed to a lower open on Wall Street Monday, as stocks were poised to trim recent gains with investors turning cautious ahead of this week's Federal Reserve meeting and a flurry of macro data.

* At 4:20 a.m. EDT, futures for the S&P 500 were down 0.5 percent, Dow Jones futures were down 0.4 percent and Nasdaq 100

futures were down 0.5 percent.

* Mining stocks will be in focus after global mining group Xstrata said it wants to merge with rival Anglo American, a deal that could be worth around $68 billion.

* Anglo shares surged 9 percent, while Xstrata shares dropped 3.7 percent.

* Investors were cautious ahead of the Federal Reserve meeting this week, bracing for the Fed's guidance on growth and any potential hints on expanding the central bank's $300 billion program of Treasuries purchases.

* The market was also fretting about the Treasury's record $104 billion worth of bond auctions scheduled this week to finance massive spending aimed at reviving the world's biggest economy.

* Also on the macro front Monday, sentiment at big Japanese manufacturing firms improved in the three months to June, data showed, but the World Bank said prospects for the global economy remain unusually uncertain as it cut 2009 growth forecasts for most economies.

* European stocks were down 0.7 percent in early trade on Monday, with oil majors such as BP, Total and Royal Dutch Shell

falling along with oil prices.

* Oil fell toward $69 a barrel Monday, extending the previous session's drop of more than 2 percent, as bearish sentiment over gasoline markets in the United States continued to dominate investors' concerns.

* The Federal Open Market Committee begins a two-day meeting on interest-rate policy Tuesday.

* The S&P 500 and Nasdaq gained ground Friday as positive broker comments on Microsoft lifted technology shares, but the benchmark indexes lost ground for the week for the first time in five weeks.

* The Dow Jones industrial average fell 15.87 points, or 0.19 percent, to 8,539.73. But the Standard & Poor's 500 Index added 2.86 points, or 0.31 percent, to 921.23. And the Nasdaq Composite Index rose 19.75 points, or 1.09 percent, to 1,827.47.

(Reporting by Blaise Robinson; editing by Simon Jessop)