UPDATE 1-BBA Aviation sees 2008 performance in line

* Trading in line with its expectations

* Sees underlying net debt lower than expected

* Shares up 9.5 percent

(Adds detail, background, share price move)

LONDON, Jan 9 (Reuters) - British aviation services company BBA Aviation (BBA.L) said performance for 2008 would be in line with market expectations, with underlying net debt lower than expected, prompting a jump of nearly 10 percent in its share price.

The company, which provides services such as engine repair to corporate jets and military planes, said in a trading update on Friday that it would be comfortably within its banking covenant limits for the year and that it had undrawn facilities of some 200 million pounds ($304.8 million) available.

At 0910 GMT, BBA's shares were trading at 86.5 pence, up 9.5 percent.

"Despite 2008 being a challenging year in many of our major markets, trading for the year has been in line with our expectations with cash flow particularly strong," chief executive Simon Pryce said in the statement.

Analysts are expecting a pre-tax profit of 81.77 million pounds for BBA in 2008 and revenue of 1.13 billion, according to Reuters Estimates. The company is due to release its full-year results on Feb. 26.

"We have significant undrawn financing available, the vast majority of our banking facilities is committed until 2012 and we will continue to focus on cash generation and debt reduction," Pryce said.

"We expect a challenging year, but are positioning ourselves to benefit from a recovery when it comes."

BBA also said its subsidiary Signature Flight Support had secured a new five-year contract with corporate plane company NetJets.

(Reporting by Catherine Bosley; Editing by Rosalba O'Brien)