The central bank is likely to say that it will start unwinding its holdings of about $4.2 trillion in bonds and mortgage-backed securities.

While a September interest rate increase is not expected, investors will closely study Yellen's views on inflation.

"Fed will likely be a non-event, but if they are slightly more dovish in their language, I think you could see a reversal in the banks, but I don't see a lot of activity," said Aaron Clark, portfolio manager at GW&K Investment Management.

"The Fed is being extremely transparent, so they don't want to surprise the market with the normalization process."

The plan will limit the amount of maturing bonds used each month to purchase new ones. The initial cut will be $10 billion per month, probably beginning in October.

Inflation has remained stubbornly below the Fed's 2-percent target rate, but a recent data showed uptick in domestic consumer prices, which raised the chances of a December rate hike by more than 50 percent.

Traders were betting on a 56.4 percent chance of a December hike, compared with 46.8 percent a week ago, according to the CME Group's FedWatch tool.

The three major U.S. stock indexes closed at record highs on Tuesday, with the financial stocks providing the biggest boost.

At 8:30 a.m. ET, S&P 500 e-minis were up 0.5 points, or 0.02 percent, with 71 contracts changing hands.

Nasdaq 100 e-minis were up 0.75 points, or 0.01 percent, in volume of 29 contracts.

Dow e-minis were up 5 points, or 0.02 percent, with 6 contracts changing hands.

Adobe fell 2.62 percent in premarket trading after the Photoshop maker's revenue forecast came in line with estimates.

General Mills was down 4.80 percent after its quarterly profit missed estimates, hurt by lower sales of its yogurts and cereals in North America.

Pfizer rose about 1 percent after Morgan Stanley upgraded stock to "overweight" from "equal weight".

Western Digital slipped 4.36 percent after Japan's embattled Toshiba said it agreed to sell its semiconductor business to a group led by U.S. private equity firm Bain Capital.

Bed Bath & Beyond sank more than 14 percent after the home furnishing retailer reported earnings and sales below estimates, prompting a slew of price target cuts.

Economic data includes a report on existing home sales that is likely to show it increased 0.3 percent in August, after falling to its lowest level in 11 months in July. The data is due at 10:00 a.m. ET.

(Reporting by Sruthi Shankar in Bengaluru; Editing by Arun Koyyur)