Jan 17 (Reuters) - Jiangxi Ganfeng Lithium Co Ltd 002460.SZ
* Says Hong Kong unit's capital will be boosted by $100 million to buy 19.9 percent stake in Lithium Americas Corp LAC.TO for $49 million
* Says unit plans to invest 503 million yuan ($73.41 million) in lithium battery project
Source text in Chinese: company coverage: 002460.SZ LAC.TO ($1 = 6.8520 Chinese yuan renminbi)