Allen & Overy (A&O) continues to sit ahead of rivals in global project financing by advising on the largest number of deals for the first half of 2008, according to new figures.

Infrastructure Journal (IJ) research shows the magic circle law firm advised on 36 deals worth a combined total of $30.5bn (£15.2bn).

Key mandates during the first six months of the year include advising on the $10bn (£4.98bn) Saudi Kayan Petrochemical Complex in Al-Jubail Industrial City. The firm advised the export credit agencies and commercial lender funding the project, fielding a team under energy and infrastructure head Anne Baldock.

A&O project finance partner Calvin Walker (pictured) said: "The Middle Eastern market appears to be largely unaffected [by the credit squeeze]. We are seeing a strong stream of work coming out of Saudi Arabia, Dubai, Abu Dhabi and Jordan."

"The experience we are having is that it is holding up surprisingly well given current market conditions. There may be a slight reduction in turnover of new deals outside the Middle East, but there is plenty of work on existing ones."

Key projects rival, Clifford Chance (CC) fell just behind the deal volume rankings after advising on 31 deals, but pushes ahead of A&O in deal value after advising on a combined worth $46.3bn (£23bn) deals.

Norton Rose sits in third place after advising on 21 deals worth $7.8bn (£3.8bn), with much of the firm's project finance work coming out of the much-touted renewable energy sector.

The renewables sector has emerged as one of the most active in Europe this year, though uncertainty over renewal of the US Government's production tax credits regime has impacted on such projects in North America.

"We are inundated with renewables work and it is not just wind – it is other green energy sources like solar, biomass and biofuels and an increase in carbon work, all due to stringent emissions requirements from the European Union [EU], Kyoto obligations and the increasing price of oil," said infrastructure partner Peter Hall.

"Looking to renewable energy is the only way the EU governments can attempt to achieve carbon emission requirements and the potential for a change in power generation is nuclear, which is being seriously considered around the world as an alternative to fossil fuels."

The firm ranked third, ahead of A&O and Linklaters in the renewables table by volume, having advised on eight deals in the renewables sector worth a combined total of $2bn (£997m) deals.

Other law firms to secure high placings on the global table include Linklaters, which advised on 18 projects, and US projects leaders Milbank Tweed Hadley & McCloy and White & Case, which both advised on 15 deals a piece.

"Given the impact of high construction costs, tight bank liquidity and uncertainty over the peg between the dollar and Gulf currencies, no-one can be certain where the overall market will go," said Milbank Tweed London managing partner Phillip Fletcher. "However, with commodity prices high, the right natural resource deals can afford to address these issues. There may be fewer deals to be done, but they will be bigger, and they will need to draw on multiple sources of funding to get done. India, Africa and the Middle East remain busy and the deals are more complex than ever."

Last year Milbank advised on two large mining deals in Africa, with Fletcher and projects partner Cathy Marsh taking lead role on the $3.3bn (£1.64bn) Ambatovy project in Madagascar and the $1bn (£508m) financing on Equinox Minerals' copper mine in Lumwana, Zambia.

According to IJ research, a total of 333 project financing deals were completed during the first half of 2008, representing a combined total of $155.2bn (£77bn).

The figures underline the extent to which top City firms are now looking to their projects and infrastructure practices to keep their finance teams busy as other key practice lines like leveraged finance and debt capital market feel the full force of the sustained credit squeeze. This a contrast to several years ago when some London firms restructured their projects teams to cope with the pressure on earnings down to the sustained slump in the dollar, in which much projects work is billed.

"The project finance market has not been heavily affected by the credit crunch – credit availability issues are affecting the work less than people think though pricing has gone up," CC project finance partner Andrew Grenville said. "Volume remains very high and there is still a demand for infrastructure. There is liquidity in the system for this type of debt."

Africa, the Middle East and the Central and Eastern European (CEE) regions are also touted by the market as seeing an increase in deal activity. Hall said: "There is a continuing increase in activity in the CEE region because it needs to invest in infrastructure and power and the domestic governments are looking to the private sector to fund that need."