Fidelity last year increased the number of BlackRock iShares ETFs offered on its platform to 65 from 30, and introduced its first full slate of sector ETFs in October with BlackRock as its sub-adviser.
The partnership allows Fidelity to further expand into the $1.7 trillion U.S. ETF market and gives BlackRock access to Fidelity's vast distribution platform.
Since Fidelity increased its iShares offering last year, investments in the iShares ETFs on its platform increased 86 percent from the year prior, with the number of Fidelity accounts holding iShares ETFs up 16 percent, the company said.