The Middle East must tread carefully to ensure it does not make the same investment mistakes as Europe, according to the CEO of the world's largest asset manager.

"The only way to get more financial inclusion in this region and every region is to have greater participation in the capital market through equities in their retirement plans," BlackRock Chief Executive Larry Fink told CNBC's Hadley Gamble during a panel session in Riyadh, Saudi Arabia on Wednesday.

"The region should not make the mistakes that so many other regions (have made), like in Europe, where there is such shallow participation by locals in investing in their own capital markets," he added.

His comments come at a time when some of the world's leading financiers are returning to Saudi Arabia after the oil-rich kingdom held some of the year's largest merger and bond deals.

International investors flocked to lend money to Saudi Arabia's hugely profitable state-owned oil company earlier this month.

Demand for Saudi Aramco's bonds surged above $100 billion, according to a source familiar with the situation, more than 10 times the $10 billion that had been expected.

Nonetheless, BlackRock's Fink said it would be "essential" for Middle East governments to drum up support from domestic investors too.

"I think that's going to be one of the critical characteristics to build and BlackRock will play a big role in both working with the domestic savers and building their retirement, plus bringing in international investing to invest side by side," Fink said.