NEW YORK (Reuters) - CIT Group Inc (CIT.N: Quote, Profile, Research) shares fell 22.1 percent on Thursday after an analyst said the finance company may have a "significant" write-down in its private student loan portfolio.

Sameer Gokhale, an analyst at Keefe, Bruyette & Woods Inc, cut his profit per share forecast to 8 cents from 76 cents for the first quarter, and to $2.71 from $3.39 for 2008.

"There is increased risk that the company will have to charge off $179 million of private student loans made to students of a flight school which recently filed for bankruptcy," Gokhale wrote.

The analyst said a majority of the students did not receive their licenses from the bankrupt school, and thus may find it harder to repay their loans. "The risk of credit losses is high," he wrote.

Despite the lowered forecast, Gokhale rates CIT "outperform" with a $39 per share price target, more than double the current share price.

New York-based CIT did not immediately return a call seeking comment.

Analysts on average expect profit per share of 92 cents for the first quarter and $4.04 for the year, according to Reuters Estimates.

CIT shares closed down $4.50 at $15.86 on the New York Stock Exchange. They earlier fell to $15.04, their lowest since Oct. 2002. The shares have fallen 70 percent in the last year.

(Reporting by Jonathan Stempel; Editing by Gary Hill)