* Chinese President Xi to make state visit next week
* Unclear if Hinkley deal will be signed during visit
* Improvement in ties after 2012 Dalai Lama dispute
LONDON, Oct 15 (Reuters) - Substantial progress has been made over a deal for two Chinese companies to help finance a British nuclear plant, one of a number of agreements on the table during Chinese President Xi Jinping's visit to Britain next week, his ambassador said.
Several pacts would be announced during the Oct. 19-23 trip, though it was still unclear whether the long-mooted deal for the Hinkley Point nuclear plant would actually be signed then, China's ambassador, Liu Xiaoming, told reporters.
The Hinkley Point project is owned by the British subsidiary of the French energy company EDF. China General Nuclear Corp and China National Nuclear Corp have been expected to take a combined stake of around 30-40 percent but the talks have taken longer than expected.
"Substantial progression has been made with regard to nuclear power," Liu added at China's embassy in central London. "Whether there will be a signing ceremony during this visit, I cannot say for 100 percent."
He did not go into details on the other deals.
Xi's state visit to Britain, where he will dine at Buckingham Palace, marks a significant improvement in ties between the two countries after Prime Minister David Cameron angered Beijing in 2012 by meeting the Dalai Lama.
China denounces Tibet's exiled spiritual leader as a dangerous separatist, a charge the Dalai Lama denies.
Several senior British politicians including finance minister George Osborne have since travelled to China to rebuild relations and Osborne was in Beijing last month to secure pledges of investment.
"Last year ... I expressed my anxiety that the UK was lagging behind some European countries in its relations with China, and it had some serious catching up to do," Liu told reporters.
"Today I can happily and confidently say that UK is coming up from behind, that the UK is committed to becoming China's strongest supporter, its best partner in the West."
Asked by British journalists whether the improved ties meant London had stopped raising the issue of human rights, ambassador Liu said China did not shy away from discussing such things but said they could not be used as a vehicle by others to interfere in Chinese affairs. (Reporting by Kate Holton)