Northwest Airlines has begun offering customers the ability to check in at its Web site for travel involving multiple airlines.

As a result of a recent enhancement to its nwa.com Check-In service, e-ticketed customers, regardless of where they purchase their ticket, can now obtain boarding passes at www.nwa.com for both their Northwest flight, and at the same time, for their connecting flight on any of six partner airlines.

The partners included in the initial launch of the new service include KLM Royal Dutch Airlines, Continental Airlines, Delta Air Lines, Alaska Airlines, Horizon Air and Hawaiian Airlines.