Chief executive officers of the largest U.S. single family offices earned a median $830,000 in 2014 including salary, bonus and long-term compensation, according to Fidelity Investments, as competition for talent boosts its value.

Three of the top four positions at the firms overseeing the wealth of single families with more than $1 billion in assets paid at least $500,000 in median total compensation, the money manager said Monday in its first major report on pay in the secretive industry. Executives are likely to see moderate raises in 2016 earnings, according to a separate study.

The rapid rate of wealth creation in the past decade by technology entrepreneurs to hedge fund titans and beyond has created a growing market for family offices. Google co-founder Sergey Brin and hedge fund manager Bill Ackman are among the billionaires who have formed such firms in recent years.

"There is more competition for family office talent," said Sarah Burley Reid, a partner in recruitment firm Spencer Stuart’s wealth-management practice. "Families are increasingly seeking higher-caliber candidates and as a result, compensation is higher."

Median pay for CEOs and the investment, operations and finance chiefs is in the six figures across family offices of different sizes but trails what top leaders at corporations got in the latest fiscal year. The 200 highest-paid executives at U.S. publicly traded companies made a median of $1.17 million in salary and $28.9 million including bonuses and stock awards, according to the Bloomberg Pay Index.

Family offices vary in structure, with some operating like an investment manager while others mainly handle household staff, taxes and travel plans.

‘Very Difficult’

“It’s often very difficult to find comparables in this space” for employee compensation, said Bobbi Bierhals, a partner at law firm McDermott Will & Emery in Chicago who counsels family offices.

Aspects of the job leading a family office merit "combat pay," Bierhals said. CEOs usually play a very personal role, acting as advisers and sometimes mediating family disputes. It’s difficult to determine how much that’s worth, she said.

Fidelity’s Family Office Services unit surveyed 216 single- family offices, which employ an average of 11 people working for 20 family members on tasks ranging from managing art collections to legal services. Sixteen percent of the firms have a family member in an executive role, the report shows.