* Uranium miner falls more than 4 pct to C$27.84
* Shares down over 23 percent since Friday
* Uranium One shares up slightly at C$3.54
* Australian uranium producers close lower
TORONTO, March 17 (Reuters) - Shares of uranium producer Cameco (CCO.TO) dipped to a six-month low on Thursday on rising concerns over an earthquake-shattered nuclear power plant in northeastern Japan, and as governments from Australia to the United States advised citizens to leave the region.
Cameco's stock has plunged by more than 23 percent since last Friday, falling more than 4 percent to hit a low of C$27.84 earlier Thursday, as the crisis in Japan led to mounting concern over the long-term outlook for nuclear power.
Shares of Cameco, the world's No.2 uranium producer, were down 4.45 percent at C$28.12 at midday on Thursday on the Toronto Stock Exchange.
The Saskatchewan-based company has plans to double its uranium output by 2018 to meet the growing demand for the nuclear fuel from countries including China, India and Korea.
But China called into question its ambitious nuclear plans on Wednesday, with the government freezing approvals on all new reactors. The Asian nation has some 27 reactors under construction and 50 in the planning stage, according to the World Nuclear Association.
Other Toronto-listed uranium producers fared better on Thursday. Uranium One UUU.TO, which had fallen over 40 percent since Friday, rose slightly to C$3.54, while Paladin Energy (PDN.AX)(PDN.TO) was up 2.78 percent at C$3.33.
In Australia, shares of Rio Tinto-owned Energy Resources of Australia (ERA.AX) fell 6.15 percent to A$7.32, while Paladin's Australian shares closed down 9.46 percent at A$3.35.
Japan has been taking desperate measures to contain a crisis at the crippled Fukushima nuclear power plant, pumping in tonnes of water to cool reactor fuel rods and contain radiation leaks.
Many countries have advised citizens to either leave Japan or move away from the northeast.
The United States chartered aircraft to help Americans leave Japan and approved the voluntary departure of about 600 family members of diplomatic staff.
The U.S. travel advisory came after Australia urged citizens with nonessential roles in Japan to consider leaving Tokyo and the eight prefectures most damaged by the earthquake. Australia cited infrastructure problems rather than radiation concerns.
($1=$0.99 Canadian) (Reporting by Julie Gordon; editing by Rob Wilson)