Raytheon Company, one of the largest US weapons makers, is expected to sign an estimated $2.1 billion deal to sell Oman an air defence system while US Secretary of State John Kerry visits the Sultanate state this week, US officials said.

One official, who spoke on condition of anonymity, told reporters the company was expected to sign a letter of intent with Oman to provide a ground-based air defence system.

The official said the terms were still being negotiated and the deal's value was not yet final.-Reuters