Complex sentence: At the time, Ocean Park was making a profit of around $1 million per year, while the JSC was operating on a deficit but these operating costs were covered by the Jockey Club, Hong Kong's largest charity.
Split into simpler sentences: At the time, Ocean Park was making a profit of around $1 million per year, while the JSC was operating on a deficit. These operating costs were covered by the Jockey Club, Hong Kong's largest charity.