Camden Council has awarded planning permission to the £135m expansion of the British Museum.

The plans received the green light at the second time of trying, after the council turned down an initial application in June 2009.

The previous, rejected plans had angered a local conservation group, Bloomsbury Conservation Area Advisory Committee (BCAAC), which claimed the development would block daylight from the existing buildings and "diminish the museum's existing architectural delights".

The rejigged plans, drawn up by architects Rogers Stirk Harbour + Partners, include sinking part of the extension below ground in an attempt to solve criticism that the extension will block views of the Grade I-listed Reading Room.

RSHP's original plans included a 1,000 sq m (10,760sq ft) building at the rear of the museum, replacing the former offices of the British Library on Montague Place, as well as a conservation centre to train museum conservators.