The world's largest missile maker, Raytheon Co, that makes the Tomahawk cruise missile is exiting its last commercial business with the sale of its its wholly owned business-jet subsidiary, Raytheon Aircraft Company, for $3.3 billion.

According to an agreement, it will sell the aircraft unit to Hawker Beechcraft Corporation, a new company formed by GS Capital Partners, an affiliate of Goldman Sachs, and Onex Partners, the Canadian buyout firm that was involved in the takeover of Australian carrier Quantas, earlier this month.

The sale of its aircraft unit is the largest divestiture by Raytheon, which makes the Tomahawk cruise missiles. Over the last decade US defence contractor has divested its commercial businesses, ranging from engineering and construction to publishing, commercial laundry, heat, air conditioning and home appliance which it had been acquiring from the 1960s through the 1990s, in an attempt at diversification.

So far it has divested 33 commercial and defence units for around $4.4 billion. Raytheon says it now plans to refocus on government and defence clients.

"The sale of Raytheon Aircraft Company further demonstrates our commitment to deliver on the company's strategy of focusing on our core government and defence business and providing the best technology, solutions and mission support to our global customers," said William H Swanson, Raytheon's Chairman and CEO.

The aircrafts unit, which makes Hawker and Premier business jets, was its last remaining commercial business. With revenues of $2.85 billion in 2005, it accounted for 13 per cent of the defence contractor's total sales of $21.9 billion.

In a communiqué, the company said that it would use the proceeds to repurchase an additional $750 million of its outstanding stock, and retire about $1 billion of debt.

The requires approval by the departments of defense, state and treasury the unit makes the T-6 trainer plane for the US defence forces and Onex, which owns an electronics firm that supplies aviation electronics for the T-6, is a non_US company.

Credit Suisse Securities (USA) LLC acted as the financial advisor and Kirkland & Ellis LLP acted as legal counsel to Raytheon.