Aug 9 (Reuters) - A conservative legal group on Wednesday urged a U.S. anti-discrimination agency to investigate Kellogg Co over workplace diversity policies that it says are unlawful, and accused the cereal maker of sexualizing its products.

This is the second complaint filed this week against a company by America First Legal, a nonprofit run by Stephen Miller, who was an adviser to former President Donald Trump.

America First in a letter to the U.S. Equal Employment Opportunity Commission (EEOC) said Kellogg's hiring, training and promotion practices are designed to achieve a balance based on race and sex that violates the federal law banning workplace bias.

It also criticized marketing campaigns including boxes of Cheez-It crackers featuring drag queen RuPaul and cereal boxes celebrating LGBTQ Pride Month.

"Management has discarded the company's long-held family friendly marketing approach to politicize and sexualize its products," the group said.

The EEOC can sue companies if it finds that their employment practices amount to illegal discrimination.

Kellogg did not immediately respond to a request for comment.

Many legal experts expect an uptick in legal challenges to corporate diversity programs in the wake of a June U.S. Supreme Court ruling barring race-conscious admissions policies in higher education.

America First in the letter said Kellogg, for example, has said it wants to have "25% underrepresented talent at the management level" by 2025 and runs fellowship programs that are only open to racial minorities.

"Kellogg’s employment practices are unlawfully based on 'equity,' which is a euphemism for illegal discrimination," Reed Rubenstein, a lawyer with the group, wrote in the letter.

America First said it also had sent a letter to Kellogg's board of directors on Wednesday threatening shareholder litigation if the company maintains the allegedly illegal policies.

The nonprofit on Tuesday sued Target Corp on behalf of an investor, saying the retailer failed to anticipate customer backlash over LGBTQ-themed merchandise that hurt its stock value.

The complaints are part of a campaign conservative legal groups and Republican legislators are waging against corporations that have enacted so-called woke policies on social issues such as race, gender and diversity. (Reporting by Daniel Wiessner in Albany, New York; Editing by Stephen Coates)