Futures Down; Citi, Berkshire Point Lower

U.S.stock index futures were lower Wednesday as central banks seemed to drift away from the idea of injecting more monetary stimulus and European shares fell.

Citigroup was set to give back some of the gains it saw a day after an upgrade from analyst Meredith Whitney.

Berkshire Hathaway also slipped after Warren Buffett announced after the market close on Tuesday that he had been diagnosed with stage one prostate cancer. Buffett told CNBC nothing had changed in the company's succession plans.

In Europe, minutes out of the Bank of England showed that only one Monetary Policy Committee member still supported quantitative easing, with ultra-dove Adam Posen giving up his long-standing call for more stimulus.

ECB policymaker Jens Weidmann told Reuters that Spain should take care of its own debt woes and ruled out a third long-term financing operation (LTRO)—or injection of liquidity—from the ECB.

In what looked like more bad news out of Europe, Portugal's prime minister wrote in an editorial in the Financial Times that the country may not return to capital markets in 2013 as previously expected.

Italy may delay by one year its plan to balance its budget and raised its budget deficit forecast.

BlackRock posted earnings that beat estimates. Adjusted earnings per share were $3.16 compared with the $3.04 analysts surveyed by Reuters had forecast.

Bank of New York Mellon reported profit in line with expectations, at 52 cents a share.

Ebay , Qualcomm and Yum Brands are among companies slated to report earnings after-the-bell tonight.

Weekly mortgage applications surged last weekas a drop in interest rates boosted demand for refinancings, though purchases fell, according to The Mortgage Bankers Association.

Crude oil inventory data will be out at 10:30 a.m. ET.

On the M&A front, SXC Health Solutions said it will acquire pharmacy benefit manager Catalyst Health Solutions in a deal valued at about $4.4 billionin cash and stock.

And Swiss food giant Nestle is nearing a deal to buy Pfizer's baby formula business for around $9 billion, according to a Wall Street Journal report.

Meanwhile, Illumina plunged after Roche decided not to extend its $51 a share tender offer for the biotech company.

—Follow JeeYeon Park on Twitter: @JeeYeonParkCNBC

Coming Up This Week:

WEDNESDAY: Oil inventories; Earnings from Ebay, Qualcomm, Yum Brands
THURSDAY: Jobless claims, existing home sales, Philadelphia Fed survey, leading indicators; Earnings from BofA, DuPont, Morgan Stanley, Nokia, Travelers, Verizon, Microsoft, AMD, Capital One, SanDisk
FRIDAY: Earnings from GE, McDonald's, Schlumberger

More From CNBC.com: