By Ben Otto 



  Power Assets Holdings Ltd.'s first-half profit fell 40% partly due to a one-off adjustment related to taxes in the UK and lower contributions from China operations. 


  Power Assets posted profit of 2.26 billion Hong Kong dollars ($291.6 million) versus HK$3.79 billion in the same period a year ago, it said in a stock-exchange filing Wednesday. 


  The global energy company said revenue fell 9.6% to HK$601 million while its share of net profit from joint ventures fell 54% to HK$1.07 billion. 


  In the the U.K., the company's largest market, Power Assets made a one-off non-cash adjustment due to the U.K. corporate tax rate remaining at 19% rather than being cut to an expected 17%. 


  Going forward, the company said, "regulatory resets, imminent in many key global markets, will pose a challenge." 


  Write to Ben Otto at ben.otto@wsj.com