Allen & Overy (A&O) has announced an 11% revenue hike at the half-year point, citing recent investment in key international markets as the principal driver of the double-digit growth.

The firm brought in revenues of £582m for the period from 1 May to 31 October, up from the figure of £526m the firm took in during the equivalent period last year.

A&O pointed to particularly strong contributions from its Australia, France, Germany, Indonesia and Washington DC offices.

Managing partner Wim Dejonghe told Legal Week: "We are quite pleased with the result so far. However, it is worth noting that the market looks better in the rear view mirror than it does on the road ahead. That looks quite bumpy and it is the same for all the firms.

"We were also pleased that our investments on the continent, where we have made a number of lateral hires in France and Germany, have paid off, with both of those practices seeing growth."

Key transactions for the firm over the six-month period have included advising on SABMiller's takeover bid for Fosters Group and on the financing of the world's largest solar photovoltaic plant – the Agua Caliente Solar Project in Dateland, Arizona.

A&O has launched 11 international offices in the last three years, most recently opening up in Washington DC this summer, as well as Indonesia and Australia last year. The firm also opened in Casablanca, Morocco, this summer, marking the firm's first office on the ground in Africa.

In a statement, Dejonghe added: "We have delivered a healthy performance in the first half of the year; however, with the Eurozone sovereign debt crisis and the US credit rating downgrade, we expect the second half to be slow. Our strategy of expansion into emerging and high-growth markets is paying off and we will keep investing in them.

The news comes as several top 30 UK firms report strong growth at the half-year point, including Olswang, which is set to report a revenue rise of more than 20%, while Ashurst and pre-merger Clyde & Co have posted 12% hikes.