Westhouse Securities has maintained its 'buy' recommendation for Africa-focused oil and gas group Bowleven after the company achieved a "key hurdle" in progressing its Etinde gas and condensate project offshore Cameroon.Following meetings last month, a formal resolution confirming Cameroon's approval of the Etinde Exploitation Authorisation Application (EEAA) has been signed.The EEAA defines the means of monetising the Etinde hydrocarbons by supplying treated gas to a government-sponsored fertiliser plant and also through a liquefied natural gas scheme. Bowleven said this was an "important step" towards the award of an Exploitation Authorisation, which will give development and exploitation rights over block MLHP-7 for an initial period of 20 years. "We think that this is the first key step that will trigger a significant de-risking of the Etinde project," according to Westhouse analysts Mark Henderson and Jamal Orazbayeva.They estimate Bowleven's 60% equity stake in the project to be worth just over $470m on an un-risked basis. However, based on current market prices, investors are only assuming a 16% probability that the project will be successfully developed, they said."Given that the resource has been discovered, that a development plan is in place and that Bowleven is getting closer to a declaration of a Final Investment Decision, we argue that the market should be attributing a much higher probability of successful development (30-40%). "We would expect the shares to rally on this news this morning," they said.The stock was up 12.6% at 38p by 09:44.BC