Refer to the input text as context and select the correct relationship between 'iShares' and 'BlackRock' from the available options.
Options: operator, owner of, product/material produced, location of formation

Trading in BlackRock Inc.’s iShares ETFs was paused more than 200 times, while those sponsored by State Street and Vanguard were halted more than 70 times, according to data from Nasdaq OMX Group Inc.
operator