Dell's stock closed at $13.27 on Monday.
Dell spokesman Jess Blackburn said in an emailed statement Tuesday that the Round Rock, Texas company does not comment on speculation.
Representatives for Microsoft and Silver Lake could not be immediately reached.
A deal would end Dell's nearly 25 years as a publicly traded company and give it the chance to attempt a turnaround away from the glare and financial pressures of Wall Street.
Dell Inc.'s stock gained 9 cents to $13.36 in premarket trading.