By Raymond Colitt and Stuart Grudgings

BRASILIA, May 13 (Reuters) - Brazil will press ahead with plans to create quotas for blacks in universities and public sector jobs to redress longstanding inequalities despite opposition, a government minister said on Tuesday.

On the 120th anniversary of the abolition of slavery in Brazil, Minister for Racial Equality Edson Santos said the reforms were essential to tackle huge disadvantages blacks still face in the job market, education and society at large.

"The abolition of slavery in Brazil was incomplete and blacks continue at the very bottom of the social pyramid," Santos told reporters.

Brazil, which was one of the last major countries to abolish slavery, claims to have the world's second-largest black population after Nigeria. Nearly half of the around 185 million population considers itself black or dark-skinned.

But to be black in Brazil is overwhelmingly to be poor. The homicide rate among blacks is 75 percent higher than among whites and 73 percent of young illiterates are black, according to a study on race the government published on Tuesday.

Proposals in Congress due to be voted on this year would make quotas for blacks obligatory in public universities, government jobs and possibly private companies as well.

The measures would also force government-sponsored advertisements to feature more blacks, who are noticeably absent from mainstream media publicity.

But there has been an opinion backlash from some quarters. And the confederation of schools and universities has challenged the legality of quotas and government scholarships based on them before the Supreme Court, which is to rule in coming weeks.

"Quotas won't solve poverty, they'll only create a racial problem where there was none," Bolivar Lamounier, a renowned Brazilian sociologist, told Reuters.

Lamounier is one of 113 intellectuals, unionists, artists and businessmen who said in an open letter that quotas are unconstitutional and discriminatory against the poor of other races.

Often held up as a model of racial harmony, Brazil has avoided violent clashes between blacks and whites in its recent history.

Brazil also never had a strong black political movement of the kind that led to civil rights reform in the United States or the end of apartheid in South Africa.

REDRESSING INEQUALITIES

The study released on Tuesday showed that most blacks still live in the ports where their ancestors arrived on slave ships or in areas where cotton or coffee were cultivated.

A survey by Brazil's IBOPE research group found that in 2007 just 3.5 percent of the country's business executives were black.

Institutional efforts to redress these inequalities, called affirmative action in the United States where quotas giving preferences to minorities arose after the civil rights era in the 1960s and have been controversial there, are new to Brazil.

In Brazil, such quotas are still voluntary. The Rio de Janeiro State University became the first university to adopt quotas for blacks only five years ago.

But the government's plan with its mandatory quotas has spurred opposition.

"Low income limits access to higher learning ... Racial quotas give a tiny minority of middle class students privileges but uphold a failed public education system," the open letter against the quotes said.

A quota committee at the University of Brasilia last year separated two identical twins into black and white, fueling the controversy.

But government officials say that without affirmative action, racial equality in Brazil would take another 500 years to achieve based on recent trends.

"We cannot wait. Our job will be done when Brazil's social pyramid is as multicolored as Brazil itself," Santos said.

(Editing by Cynthia Osterman)