One of the reform petition's architects said on Tuesday that it partly attributed Islamist violence in Saudi Arabia to the absence of political participation.
The reformer, who declined to be named, said the petition - the second since September - asked the ruling family to give ordinary Saudis a say in affairs of state and transform the absolute monarchy into a constitutional one similar to Jordan or Bahrain.
It also reiterated calls for an elected parliament, an independent judiciary and equal rights for women, who are not allowed to drive in the ultra-conservative Muslim kingdom.
"This document has been signed by academics, Islamic judges and scholars, former ministers, human rights activists and other key personalities in society," the reformer said.
"We wanted to be convincing and to tell the ruling family that this is the opinion of those who want reform because they care about our country and want to see it prosper."
He said the document was mailed to Saudi Arabia's de facto ruler Crown Prince Abd Allah and several ministers last week.
More than 50 people - Saudis and foreigners - have been killed since May in a string of human bombings believed to be linked to Usama bin Ladin's al-Qaida network.
Saudi Arabia is ruled by the House of Saud and members of the family also hold key positions.
"We wanted to be convincing and to tell the ruling family that this is the opinion of those who want reform"
Crown Prince Abd Allah appeared to heed growing calls for reform in October, announcing the oil-rich kingdom, which has a fast-growing, youthful population and high unemployment, will hold its first ever municipal election next year.
The US has also pressured Saudi Arabia to reform to undermine Islamist fighters who oppose the kingdom's absolute monarchy and its Western ties.
Most of the hijackers who carried out the 11 September attacks on US cities were Saudis.
In September, a group of some 300 reformers urged Prince Abd Allah to move faster on political and social reforms to curb the Islamists' growing influence. Saudi liberals have in the past submitted similar reform petitions.