BEIJING, Aug 30 (Reuters) - Bank of China Ltd (BoC) (601988.SS), the country"s fourth-largest lender by assets, posted a 11.8% increase in first-half net profit on Monday, the biggest jump since 2013 as business activity recovered from the COVID-19 pandemic. Profit was 112.8 billion yuan ($17.44 billion) in the six months ended June 30, according to the lender"s statement to the Hong Kong stock exchange, versus 100.9 billion yuan a year earlier, when the government implemented measures to contain the health crisis. The first-half figure implies profit of 60.2 billion yuan for the April-June quarter, up 24.6% from 48.33 billion yuan a year prior, Reuters calculations showed. ($1 = 6.4668 Chinese yuan renminbi)