Looking at the DL partner awards chart, it appears that only KE allows upgrades using DL miles when purchasing a KE ticket.

If the flight also operates as a Delta code-share on SkyTeam partner metal, Delta usually purchases business class seats in addition to coach seats. You should be able to use DL miles to upgrade your DL ticket; however, if you think DL imposes strict capacity controls for free or upgrade seats in BE, its worse on codeshares. DL usually only purchases a handful of business seats.

[This message has been edited by FTraveler (edited 09-01-2001).]