Before revision:  Although the market maker can ask its OTC counterparties to transact a block trade without causing a direct price impact in the exchange, its timing is assumed to be uncertain. Another important way for the market maker to reduce its position is to match an incoming customer order to the outstanding position being warehoused in its balance sheet .
After revision:  Although the market maker can ask its OTC counterparties to transact a block trade without causing a direct price impact .