* Decides not to appeal a court summons to testify
* To appear before a Palma de Mallorca court
* Lawyers deny charges, say princess has 'nothing to hide'
By Inmaculada Sanz and Tracy Rucinski
MADRID, Jan 11 (Reuters) - Spain's Princess Cristina, daughter of King Juan Carlos, will appear before a Palma de Mallorca court to testify over tax fraud and money-laundering charges she denies but has decided not to appeal, her lawyers said on Saturday.
It is the first time a member of Spain's royal family will testify as the subject of criminal proceedings since Juan Carlos came out of exile to reclaim the throne after the end of the Francisco Franco dictatorship in 1975.
"Her Royal Highness has decided to renounce her right to appeal ... and to appear voluntarily before the judge," her law firm Roca Junyent said in a statement.
However, the lawyers said they "absolutely and firmly disagree" with the charges brought against Princess Cristina, which were made public this week by Palma de Mallorca Examining Magistrate Jose Castro after a lengthy investigation.
The case is centred on Princess Cristina's involvement in a charitable organisation called Noos Foundation run by her husband, former Olympic handball player Inaki Urdangarin.
Urdangarin was earlier charged with fraud, tax evasion, falsifying documents and embezzlement of 6 million euros ($8.2 million) in public funds through Noos, which put on sports business conferences in Mallorca and across Spain.
Urdangarin has denied any wrongdoing.
This week's summons called for Princess Cristina, 48, to testify on March 8 but her lawyers on Saturday asked that the testimony take place as soon as possible to avoid drawing out what they called "an uncomfortable and unjust situation".
"She has nothing to hide before the judge," her lawyers said.
The case is one of many high-level corruption scandals in Spain that have undermined faith in public institutions at a time of economic crisis, marked by deep cuts in public spending.
Opinion of the royal family in particular has sunk to its lowest level ever.
"The royal household believes Princess Cristina's decision to testify is very positive," a spokesman for the royal household said on Saturday, but declined to comment further. ($1 = 0.7314 euros) (Editing by Julien Toyer and Sophie Hares)