The rising value of the dollar is hurting American businesses and could ultimately result in a slowdown in future U.S. growth, BlackRock Chief Executive Officer Larry Fink warned in a letter scheduled to go out to shareholders next week.

The dollar's gain of 25 percent since July against a basket of major currencies has landed a double whammy on U.S. companies with big sales abroad. Revenue and earnings from foreign markets are worth less when translated into greenbacks, and their costs become relatively less competitive against rivals producing in countries with declining currencies.

Fink, in his letter, said he was worried about the implications of the rising dollar on the U.S. economy overall as company CEOs became increasingly nervous.

"While the U.S. economy as a whole is not overly exposed to exports, many of our largest and most influential companies are," Fink wrote in the letter, which was attached to a regulatory filing with the Securities and Exchange Commission Monday.

"We believe that this will lead to an erosion in confidence on the part of CEOs, with the potential to slow both investment decisions and future growth in the U.S," he said.

Meanwhile, Fink believed lower oil prices should benefit economies globally but cautioned there would be volatility as "high-cost energy production economics are experiencing headwinds."

He wrote in the letter: "More shocks can be expected as production decisions and the demand side seek equilibrium, but ultimately lower energy prices should benefit the global economy."