UPDATE 2-Finmeccanica H1 profit down 20 pct, below forecast

* H1 net profit 194 mln euros vs f'cast 223.8 mln

* Confirms 2010 sales, EBITA targets

* Order book 45.8 bln euros end June vs 45.1 bln end 2009

* Net debt 4.6 billion euros, up 0.2 pct

* Shares close up 0.4 percent ahead of results.

(Adds details on debt restructuring paragraph 4, 6)

ROME, July 28 (Reuters) - Italy's top defence and aerospace company Finmeccanica SpA (SIFI.MI) said on Wednesday its net profit in the first half of the year fell 19.8 percent, missing estimates, as higher financial costs weighed.

The Rome-based company, which assembles military jets and builds electronic warfare systems, reported first-half profit of 194 million euros ($252.5 million). The results compared with a Thomson Reuters I/B/E/S estimate of 223.8 million.

Finmeccanica said its order book ensures more than 2-1/2 years of production. It confirmed its targets for 2010 sales and EBITA and said it had asked banks to extend credit lines to 2015.

Chief Financial Officer Alessandro Pansa told reporters the higher financial costs which weighed on profits were linked to debt restructuring, with average maturities being extended to 10-1/2 years from 3-1/2 years.

Bankers told Reuters earlier on Wednesday that Finmeccanica was asking lenders for a 2.4 billion euros ($3.1 billion) loan refinancing.

Finmeccanica said its net debt was up 0.2 percent from the first half of 2009 at 4.6 billion euros. Pansa reiterated the company's target to cut debt to 3.2-3.3 billion euros by end 2010.

Shares in the company, down 17 percent in the last six months, closed up 0.4 percent at 8.81 euros before the results. Milan's top 40 stocks .FTMIB ended 0.33 percent higher.

Finmeccanica has been in the spotlight in recent weeks over a judicial probe into the Digint security software company in which it has a stake. The company has repeatedly denied Italian media reports that it had set up slush funds abroad. (Reporting by Paolo Biondi; Editing by David Holmes and Elaine Hardcastle) ($1=.7684 Euro)