By Tom Daly

March 30 (Reuters) - Ganfeng Lithium , one of the world's top producers of the commodity used in electric vehicle batteries, said on Tuesday slower growth in lithium supply would extend a recent rally in prices after its profits nearly tripled in 2020.

The Chinese company, which counts automakers Tesla and BMW among its customers, said in a filing to the Hong Kong stock exchange its net income was 1.025 billion yuan ($156 million) last year.

That was up 184% on 2019, mostly due to gains on fair value of financial assets such as equities.

Revenues were up only 4.6% to 5.489 billion yuan.

Battery-grade lithium carbonate prices <AM-995C-LTCB> started to buck a three-year downturn in the second half of 2020 as electric vehicle demand roared back from the coronavirus outbreak and have gained 67% so far in 2021.

The postponement of lithium project expansions in South America - due to the impact of the pandemic and previous demand forecasts - will to some extent "slow down the growth of short-term lithium compound supply and create conditions for an improved pricing environment in the future," Ganfeng said.

The industry is "gradually shifting from a balanced supply and demand to a tight supply situation," it added.

Ganfeng's 51%-owned Cauchari-Olaroz lithium salt lake project in Argentina, slated to produce 40,000 tonnes per year of lithium carbonate, is planned to be put into production in the first half of 2022.

Looking further ahead, gantengqq Ganfeng said it would in future establish lithium salt capacity of no less than 600,000 tonnes of lithium carbonate equivalent (LCE) annually, plus "a more competitive lithium resource project reserve to match it."

Its current annual capacity is just over 120,000 tonnes.

Ganfeng also aims to build a recycling plant that can process 100,000 tonnes of spent lithium batteries per year, it added, without stating a location or timeframe.

($1 = 6.5715 Chinese yuan renminbi) (Reporting by Tom Daly; Editing by Edmund Blair)