The British energy supplier won the UK CSR Online Awards - a ranking of the online CSR communications based on the responses of 184 CSR professionals across the globe.
Centrica's site was praised for its interactivity and ease of navigation, as well as its environmental commitment and privision of space to discuss CSR hot-topics.
Energy and natural resources firms dominated the top of the rankings with Royal Dutch Shell, Rio Tinto, Tesco and BHP Billiton making up the rest of the top five respectively. BP and Unilever were tied for sixth, followed by National Grid and Xstrata.
Lundquist said that most of the companies provided a sufficient range of information online, but that a significant minority failed to go beyond communicating basic content and that interactivity remained ‘weak'.
In global terms, British companies performed better than its international peers - with seven UK firms in the top 20 globally.
‘Leading UK companies in online CSR communications are among the best internationally, but there's no room for complacency,' said James Osborne, head of CSR communication at Lundquist. ‘Many companies are stuck in an ‘offline' mode of disclosure and reporting, with little space for feedback and dialogue.'
The average raking of the 19 UK companies included in the global study was 53.5 points, putting them ahead of the rest of Europe (average 51.8), Asia (43.4) and the American (43.6).
The global award was taken by Italian oil and gas firm Eni, followed by Swiss bank UBS.
A total of 76 criteria were used to judge online CSR performance, divided into 18 sectors looking at both content and online presentation.