The owner of Carat, Vizeum, Synovate and Posterscope reported a 4.2% rise in revenue to £663.3m, while earnings per share rose by 2.7p to 3p.
Buhlmann, who took over from interim chief executive and chairman John Napier, said: "We produced a strong performance during the first half of 2010, confirming our expectations of a return to growth.
"This was driven by good performances from our businesses in faster-growing regions, Synovate's return to profitability and strong net new business wins totalling $1bn of billings from Aegis Media."
The rise in profits came as research arm Synovate bounced back from making a loss in the first half of 2009, when Aegis spent £15.7m on restructuring costs, as it sought to cope with the financial downturn. There were no such costs this year.
New business wins during the period came from brands including Bhs, which handed its £2m account to Carat, and BT, which awarded its 2012 Olympics planning brief to Vizeum.
Aegis said it planned to build on growth in the Aegis Media division by increasing exposure to faster-growing regions and broadening its geographic reach to target more international clients.
Aegis had been without a group chief executive for a year and a half after the departure of Robert Lerwill.