National Public Radio: MARY LOUISE KELLY, host: To BP news now: The company says the oil spill in the Gulf of Mexico has already cost it more than $3 billion. It also says it wants some of its corporate partners in the well to pay for part of the cleanup. NPR’s Jim Zarroli reports. JIM ZARROLI: BP released updated figures yesterday for how much the Gulf spill has cost it, and the numbers keep rising. So far, the company says it has paid $3.12 billion to contain the spill, drill a relief well …