Correction: Adds the business might generate $75 million in annual after-tax profits for JPMorgan in the fifth paragraph.

NEW YORK (TheStreet) -- Southwest Airlines (LUV) - Get Report is considering replacing JPMorgan Chase (JPM) - Get Report as the issuer of its credit card rewards program, according to two people familiar with the matter.

One of those people said Southwest has hired investment bank First Annapolis as an adviser as it reviews the relationship with Chase. John Grund, who manages the credit card M&A advisory business at First Annapolis, did not respond to calls. Spokespeople for Chase and Southwest declined to comment.

While the size of the Southwest program could not be determined, both sources said it is considerably larger than $1 billion in receivables, while one said it is "several multiples of that," and considerably larger than one would expect from an airline the size of Southwest. The other source, however, said it certainly didn't approach $10 billion. For comparison Costco's (CSCO) - Get Report receivables, recently shifted from American Express (AXP) - Get Report to Citigroup (C) - Get Report, are about $14 billion.

Assuming a $5 billion receivables program, JPMorgan might be expected to hold $500 million in equity against those loans. Assuming a 15% return on equity, it means the business might generate $75 million in annual after-tax profits for JPMorgan, according to Sameer Gokhale, credit card industry analyst at Janney Capital Markets. Gokhale stressed that the figures were rough assumptions as he does not officially cover JPMorgan and doesn't know the size of the Southwest portfolio.

Retailers typically review their relationships with credit card issuers at least a year before they expire and sometimes as long as two years in advance, and the process has just begun.