Sinn Fein MLA Caitriona Ruane had put forward the petition of concern, supported by Alliance Party MLA Anna Lo, and Green Party MLA Stephen Agnew.

BBC: NI Assembly fails in bid to change abortion law

The joint Green Party and Alliance motion was opened by Anna Lo who said the four licences for exploration for hydraulic fracturing, known as "fracking", had been granted despite a "severe deficiency of research".

BBC: Hydraulic fracturing

Alliance MLA Anna Lo said Northern Ireland was missing out on thousands of jobs in the green economy sector, on 12 September 2011.

BBC: Green economy (continued)