Speaking at a civil rights meeting in New York on Saturday, Jackson claimed there was a "conspiracy" among record companies.
"The record companies really do conspire against the artists, especially the black artists," Jackson told a crowd of around 350 people at Sharpton's National Action Network headquarters in Harlem.
A spokesman for Sony - Jackson's record label - responded to the singer's criticisms, saying the remarks were "ludicrous, spiteful and hurtful".
Jackson alleged that generations of black musicians had not gained the success and profits they deserved because of the power of record companies.
He also accused an executive of Sony of using racist language to refer to black artists.
The Sony spokesman said the attack was "bizarre... unwarranted and ugly".
Risks
Later on Saturday, a group of fans, including Jackson look-alikes, gathered outside Sony's Manhattan offices to call for a boycott of their products.
The fans were demonstrating against what they believe to be Sony's inadequate promotion of Jackson's latest album Invincible, which has had disappointing sales.
Charges that record companies exploit minority artists have been voiced before.
In particular, there have been claims that African-American artists have had money generated by their creativity and performances withheld.
The record industry has defended itself by emphasising the financial risks taken on by record labels when they sign new artists, many of whom fail to make money.