Delta's mainline flights were on-schedule 83.7 per cent of the time in the 12 months through December, data shows.
If American and United beat Delta's on-time and completion rates for a year, Delta would award travel credits of US$1000 ($1590) to US$250,000 to businesses with a contract. Those who suffer the most delays and cancellations get the biggest payouts.
There are enough caveats, however, that it's unlikely Delta will have to pony up, said Barry Rogers, a corporate travel adviser.
By measuring on-time or cancellation rates over a full year, it can't be held accountable for short-term hiccups. The offer also excludes international flights, the regional affiliates, which have spottier reliability records, and industry leaders Alaska Airlines and Hawaiian Airlines. Delta also must trail both American and United - not one or the other - and United has been mostly stuck in the bottom half of US carriers in recent years.
A few airlines have given a reliability guarantee "lip service", Rogers said, but no one else has moved forward.
Big companies have many considerations to weigh when making corporate travel decisions, and discounts on airfare are huge motivators, said Brad Seitz, a corporate travel consultant.
Some businesses can command half off pricey last-minute fares. Still, Delta's on-time guarantee is generating some buzz, he said.
"Now they're saying, 'Does this mean anything or is it just a marketing ploy?'" Seitz said.
On time
• Delta's mainline flights on-schedule 83.7% of the time.
• Airline jumped 10 spots in 2011 and is now in third place.
• Carrier will award travel credits to corporate clients if it falls behind rivals American Airlines and United Continental.
- Bloomberg