. the underlying physical contract is for a specified annual quantity of gas and matures in 2008 . similarly , marathon will use derivative instruments to convert shorter term ( typically less than a year ) fixed price contracts to market prices in its ongoing purchase for resale activity ; and to hedge purchased gas injected into storage for subsequent resale . derivative gains ( losses ) included in oerb segment income were $ 19 million , $ ( 8 ) million and $ ( 29 ) million for 2003 , 2002 and 2001