Canamens BNG is not making the final payment to AIM-quoted oil and gas explorer Roxi Petroleum for the purchase of BNG Ltd, which has a stake in exploration interests in Kazakhstan.This could impact the longer-term development of the interests because more cash will be needed to develop them. The payment that has not been made totals $11.98m and relates to a deal approved by Roxi shareholders in November 2009. Roxi says that this means that Canamens will forfeit a 6.25% interest in the BNG contract area to Roxi. That would take Roxi's stake to 29.66% and Canamens would own 28.75% - subject to Kazakh government approval.Baverstock GmbH, a company controlled by Kuat Oraziman, a director of Roxi and its largest shareholder, owns the other 40.59% of the contract area.Roxi acquired its interest in the BNG contract area in March 2008 and in January 2009 agreed to sell a 35% stake in the contract area to Canamens in two stages. It paid $2m plus funding commitments of $32m for 23% and has subsequently paid a further $9m.