NEW YORK (CNN/Money) - Investors will cast their attention to Comcast Corp.'s $66 billion offer for Walt Disney Co. as another sign of a revival in merger and acquisition activity when trading begins Wednesday.

Early Wednesday, futures pointed to little change at the open for the major indexes but turned positive about 7 a.m. ET after Comcast announced its bid.

Comcast said it made a proposal to acquire Disney in a tax-free transaction valued at $66 billion, including the assumption of debt.

Comcast (CMCSK: Research, Estimates) said it would issue 0.78 share of Comcast Class A shares for each Disney share. Disney shareholders would receive a premium of more than $5 billion based on Tuesday's closing prices, the cable company said.

It added that Disney (DIS: Research, Estimates) Chairman Michael Eisner has been unwilling to discuss a possible transaction.

Eyes will also turn to Alan Greenspan's House testimony, Sen. John Kerry's primary wins and earnings from two Dow components Wednesday.

For details of Tuesday's gains, click above

Federal Reserve Chairman Greenspan appears Wednesday morning before the House Financial Services Committee to give his semi-annual assessment of monetary policy. He is likely to be probed about the state of the economic recovery, about interest rates and especially about the deficit. If, as some reports have indicated, Greenspan is looking to make a major statement opposing large deficits, this might be the forum.

Kerry's path to the Democratic presidential nomination went through the South on Tuesday night as the senator from Massachusetts captured primaries in Virginia and Tennessee, in the process apparently knocking out retired Gen. Wesley Clark. He holds a big lead in delegates to the convention as the race moves to Nevada this weekend and Wisconsin next week.

In corporate results, Coca-Cola (KO: Research, Estimates) reported a flat profit of 38 cents a share compared to a year earlier.

After the close, the results are due from Walt Disney (DIS: Research, Estimates), where chairman Michael Eisner is under siege from dissidents led by the nephew of the company's namesake. The company's fiscal first-quarter earnings are seen rising to 21 cents a share from 17 cents a year earlier.

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On Tuesday, the parent of ABC television and the Disney theme parks company said the company's board is considering a succession plan for Eisner.

Among U.S. stocks trading in Europe, Disney was down in early trading, but jumped after the Comcast offer.

The Dow Jones industrial average is coming off a 0.3 percent rise in Tuesday's session, while the Nasdaq composite index was 0.7 percent higher (see chart for details).

Asian-Pacific stocks ended mostly higher Wednesday; Japan's markets were closed for a holiday. European markets were mixed in early trading. (Check the latest on world markets)

Treasury prices held steady, with the 10-year note yield at 4.11 percent. The dollar edged up against the euro and was little changed versus the yen.

Brent oil futures slipped 23 cents to $29.70 a barrel in London, a day after OPEC announced a surprise production cut in order to prevent a steep price decline in the spring. Gold prices eased.