BEIJING, April 5 (Reuters) - The chairmen and presidents of China’s five biggest banks saw their 2015 compensation slashed by a record 50 percent, the lenders’ annual reports showed, after Beijing-mandated pay reforms for executives of state-owned firms were implemented last year.

Jiang Jianqing, chairman of Industrial and Commercial Bank of China (ICBC) , the world’s biggest lender by assets, made less than 550,000 yuan ($85,000) in total compensation last year, down 52 percent from 1.1 million yuan in 2014, according to the bank’s latest annual report.

That was only 0.3 percent of the $27 million total compensation received by JPMorgan Chase & Co Chief Executive Jamie Dimon in 2015. It was also a fraction of the 14.3 million Swiss francs ($14.8 million) that UBS Chief Executive Sergio Ermotti received in total compensation for 2015.

The hefty pay cuts for its top bankers came as China’s weak economy pressured the lenders’ profits. China’s big banks last month reported their weakest profit growth in a decade, with interest margins shrinking in the face of successive interest rate cuts, and non-performing loans at a 10-year high.

Beijing is aiming to transform executive compensation at its biggest state firms by cutting salaries, curbing misuse of non-salary benefits and holding managers responsible for the performance of their firms, as part of the government’s state-owned enterprise reform efforts.

Under the plan, which is being implemented from 2015, top bosses at 72 central government-owned firms, which also includes well-known conglomerates such as PetroChina Co Ltd, China Petroleum & Chemical Corp (Sinopec) and China Mobile Ltd face pay cuts of as much as 50 percent.

China Construction Bank , the country’s second-biggest lender, slashed chairman Wang Hongzhang’s annual compensation to less than 600,000 yuan in 2015 from 1.2 million yuan in 2014, the bank’s annual report showed.

The chairmen at another three major Chinese state lenders - Agricultural Bank of China , Bank of China and Bank of Communications - also only pocketed half of what they earned in 2014, their annual reports showed.

Besides the chairmen of the lenders, their presidents also saw their compensation halve in 2015, the reports showed. ($1 = 6.4696 Chinese yuan renminbi) (Reporting By Shu Zhang and Matthew Miller; Editing by Muralikumar Anantharaman)