WASHINGTON (Reuters) - Two legal challenges to the Voting Rights Act, a landmark law adopted in 1965 that barred racial discrimination in voting practices, reached the U.S. Supreme Court on Friday.

The appeals target a part of the law, known as pre-clearance, that says that states with a history of discrimination must get permission from the federal government before changing election procedures.

The first challenge was filed by supporters of a 2008 Kinston, North Carolina, measure that would omit candidates' party affiliations from ballots.

The Obama administration used the pre-clearance requirement to block the Kinston measure in 2009, saying black voters would be more likely to vote for the wrong person under the new rules.

Later on Friday, lawyers for Shelby County, Alabama, filed an appeal of their own. The county sued to challenge the law in 2010 in a case many considered destined for the Supreme Court.

Both appeals argue that the pre-clearance requirement unfairly targets selected governments based on a decades-old formula. They ask the Supreme Court to review their cases this term, which begins in October.

There have been more challenges to the Voting Rights Act in the past two years than in the previous 45 year, including recent Section 5 lawsuits from Texas and South Carolina.

(Reporting by Drew Singer; editing by Kevin Drawbaugh and Andre Grenon)