(Adds Palestinian comment, paragraph 7) JERUSALEM, March 14 (Reuters) - A third of Israeli settlements in the occupied West Bank are built on private Palestinian land, an anti-settlement group said in a report on Wednesday. The left-wing group Peace Now said 32.4 percent of the land held by Jewish settlements in the West Bank was privately owned by Palestinians. An earlier report by the same group estimated the figure at 40 percent. Peace Now said it based its new findings on the database of Israel's military-run Civil Administration in the West Bank. The Civil Administration said in response: "We were disappointed to see that despite the clarifications made by the Civil Administration ... the most recent report is still inaccurate in many places, thus misrepresenting the reality concerning the status of the settlements." The Civil Administration disputed the way Peace Now defined the boundaries of many settlements. The Palestinians, who want all the West Bank along with the Gaza Strip for a future state, and human rights groups have long accused Israel of illegally expropriating "state land" for the purpose of building settlements. "This is the biggest proof that Israel wants the land while talking about peace. Settlement expansion and the theft of our land has never stopped," Nimer Hammad, an adviser to Palestinian President Mahmoud Abbas, said about the Peace Now report. Israel has long maintained that Jewish settlements, which are illegal under international law, were built on "state lands", or areas not registered in anyone's name, and that no private property was being seized for settlement building. Peace Now said last month that Israel was building more than 3,000 homes in Jewish settlements in the West Bank, and that while the number of settlements did not grow in 2006, their population had increased over the year by 5 percent. About 2.4 million Palestinians and 260,000 Jewish settlers live in the West Bank, which Israel captured in the 1967 Middle East war but stopped short of annexing. (Additional reporting by Mohammed Assad in Ramallah)