Spirit Airlines Inc. said Wednesdy it is postponing the special shareholder meeting relating to its proposed merger with Frontier Airlines Inc. to June 30 at 9 a.m. Eastern. The move will allow the carrier’s board continue talks with its shareholders, as well as with Frontier and JetBlue Airways Corp. , which has launched an unsolicited competitive bid for the company. “Spirit remains bound by the terms of the merger agreement with Frontier, and Spirit’s Board has not determined that either JetBlue’s unsolicited tender offer or its updated proposal received on June 6 constitutes a Superior Proposal as defined in the merger agreement with Frontier and has made no change to its recommendation that Spirit stockholders adopt the merger agreement with Frontier,” the company said in a statement. JetBluesweetened its bid on Monday with a $350 million reverse break-up fee payable to Spirit should the deal fail on antitrust grounds, up from an earlier offer of $200 million. Spirit shares were down 1.2% premarket, while Frontier was not active and JetBlue was up 0.6%.

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