INDIANAPOLIS (AP) -- The parent company of Frontier Airlines says a deadline to sell the airline will be extended by two more days.

Republic Airways, Frontier's owner, has agreed to sell it to Indigo Partners, an investment firm based in Phoenix. But before the sale can close, Indigo says it needs agreements with the union for Frontier flight attendants, and with credit card issuer Barclays.

Republic said Tuesday that Indigo has informed it that "good progress" is being made in the talks but no deal has been reached yet. Monday was the original deadline for Indigo to terminate the deal.

Indigo has said it wants to turn Denver-based Frontier into an ultra-discount airline.

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