Reuters reported that Dell was in talks with banks about raising debt financing for an all-cash offer for EMC. The terms of the negotiations were not immediately known, Reuters noted, adding that EMC had a market capitalization of about $50 billion as of Wednesday's close.
If the deal went through, it would be one of the biggest tech tie-ups ever, topping U.S. chipmaker Avago Technologies' $37 billion offer for rival Broadcom. That deal is still in process.
The Wall Street Journal, which first reported the deal talks, wrote that EMC had started a strategic review of its business last year, while Reuters reported that EMC had been under pressure from activist investor Elliott Management, which had lobbied for EMC's VMWare software business to be spun off.
A deal was not certain, according to the WSJ report. The WSJ had reported in September that EMC was in talks with both Dell and rival Hewlett Packard.
EMC shares rose nearly 8 percent in extended trading Wednesday. Dell became a private company in 2013, delisting its shares in October of that year.
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A spokeswoman for Dell told CNBC that the company did not comment on rumors or speculation. When contacted by Reuters, an EMC spokesman declined to comment.