UPDATE: Morgan Stanley Downgrades JetBlue Airways to Underweight

Morgan Stanley is out with its report today on JetBlue Airways (NASDAQ: JBLU), downgrading JBLU to Underweight.

In a note to clients, Morgan Stanley writes, "We believe JBLU's maturing low cost / low fare model will have difficulty maintaining current margins longer-term as growth opportunities become limited and competition in the company's markets intensifies. As a result, we see less upside in JBLU relative to the other airlines in our coverage; thus, we are downgrading to Underweight."

Shares of JBLU closed Friday at $6.25, up 2.46% from Thursday's close.