Shares of Spirit Airlines are up 20% after a report that JetBlue has made an offer

shares Spirit Airlines It rose more than 22 percent on Tuesday after a report that JetBlue Airways He made a bid for the budget carrier, raising questions about Spirit’s deal to merge with rival discount company Frontier Airlines.

Spirit confirmed after the market closed on Tuesday that JetBlue had made an unsolicited bid.

JetBlue view, which I reported earlier New York timescomes less than two months after Spirit and Frontier agreed to merge into the discount airline giant.

Spirit said its board of directors was evaluating the JetBlue proposal and would “pursue the course of action it sets out to be in the best interest of Spirit and its shareholders.”

The competition for Spirit is showing a renewed appetite for integration into the airline industry as it works its way out of two tough years from a pandemic that has battered travel demand. Carriers are now scrambling to hire in the face of a rebound in travel.

The merger wave that began more than a decade ago has left four major airlines controlling more than 70% of the US market.

Trading in Spirit was halted before the market closed. Its shares were at $26.93. JetBlue offered $33 a share in its entire cash offer, according to Spirit.

JetBlue and Frontier did not immediately comment on CNBC.

JetBlue shares closed down about 7%.

Both Spirit and Frontier fly only Airbus A320 family aircraft. These make up the majority of the JetBlue fleet, which will reduce costs and logistical headaches in combining carriers.

However, JetBlue has a partnership with American Airlines Which allows carriers to coordinate service in the northeastern US The two airlines said the agreement would give them a better chance of competing against United and Delta Airlines At busy airports in New York and Boston.

The Justice Department filed a lawsuit to block that partnership last year.

American declined to comment on JetBlue’s bid to buy Spirit.