Norton Rose has taken a lead role on a multibillion-pound cross-border project finance deal to develop a new security headquarters for the government in Saudi Arabia.

The City law firm has advised longstanding client Saudi Oger on the first stage of financing for a project to build new security headquarters for the Saudi Ministry of Interior across various parts of the country.

Financing for the project, which is expected to cost 
more than SAR19bn (£3.1bn), saw Saudi Oger initially agree debt and advance payment guarantee facilities arranged 
by the London branch of Deutsche Bank.

City finance partner Alexandra Triptree led the Norton Rose team, with Allen & Overy (A&O) advising the banks through a Middle East-based team, including Dubai partners Ian Ingram-Johnson and Saudi-based partner Julian Johansen.

Clifford Chance's Saudi ally Al-Jadaan Law Firm won a role advising Saudi Oger on local law aspects of the transaction.

Triptree said: "We were delighted to work with Saudi Oger on the first phase of this complex financing which was completed in a short timeframe notwithstanding continued uncertainty in the Middle East."

Saudi Oger is a private company incorporated in Saudi Arabia which specialises in the construction, maintenance and telecoms sectors. It has offices throughout Saudi Arabia, Europe and the Middle East. Norton Rose has previously advised the company on deals including the 2009 sale of its interest in Romanian mobile operator Telemobil.