By DAVID KOENIG
AP Airlines Writer
JetBlue Airways is trying to buy Spirit Airlines and break up a plan for Spirit to merge with fellow budget airline Frontier. Spirit said Tuesday that JetBlue offered $33 a share, or about $3.6 billion. Florida-based Spirit says its board will evaluate the JetBlue bid and decide what’s best for its shareholders. The JetBlue offer is about 40% higher than the value of Frontier’s bid. Frontier’s offer in cash and stock was worth $2.9 billion when it was announced in February, but Frontier shares have fallen since then, reducing the value to Spirit shareholders. Spirit shares soared after the New York Times reported JetBlue’s bid earlier Tuesday.