Exxon Mobil, Chevron, ConocoPhillips and Royal Dutch Shell plan to build a $1 billion rapid-response system to capture and contain oil in the event of a future underwater well blowout.

The four companies will contribute $250 million each toward the creation of a non-profit organization, the Marine Well Containment Co., that will develop and manage containment equipment and responses in the Gulf of Mexico, Alan Jeffers, an Exxon spokesman, said.