Kosmos finds gas in Mauritania as regional exploration picks up

* Kosmos says find confirms its commercial potential

* Exploration is picking up in Transform Margin

* Shares (Berlin: DI6.BE - news) rise nearly 15 percent (Changes dateline, recasts, adds detail)

NOUAKCHOTT/NEW YORK, April 27 (Reuters) - Kosmos Energy (NYSE: KOS - news) said on Monday it had made a significant gas discovery offshore Mauritania, driving its shares higher and raising its hopes for further finds in the region.

Recent drilling success and relatively low costs have boosted interest in the stretch of waters off the northern coast of West Africa, known as the "Transform Margin", analysts and executives say.

New York-listed Kosmos said the discovery of a gas pool in the Tortue 1 exploration well, part of its Greater Tortue Complex which extends southwards to northern Senegal, confirmed the commercial potential of the prospect.

The stock was last up nearly 15 percent at $9.99 in heavy trade and was on track for its biggest daily percentage gain since the company's flotation in 2011.

An official at Mauritania's state oil company, a minority stakeholder in the asset, said further drilling was planned in the next few days to confirm the scope of the discovery. A unit of Chevron Corp has the option to take a 30 percent stake in the Tortue prospect, subject to paying a share of the costs, the Kosmos statement said.

Mauritania pumps less than 5,000 barrels of oil per day, according to International Monetary Fund figures, but Senegal has no production. Fresh discoveries could transform the fortunes of countries ranked as lower-middle income by the World Bank.

Last year, Kosmos agreed to a $400 million farm-in agreement with Senegal's state-owned Petrosen and privately owned Timis Corp, although it has given no time frame for drilling.

Since then, Kosmos has conducted seismic studies offshore Senegal and is processing the results. Oil explorer Cairn Energy (LSE: CNE.L - news) last year made two discoveries in Senegal, one of which it says may be the biggest oil discovery of 2014.

Research and consulting firm GlobalData said exploration success in the area was at around 65 percent in the West African Transform Magin. According to its count, there are seven upcoming wells in Senegal and Mauritania.

"The Transform Margin is seen as a key exploration area in Africa; hence the initiatives by companies, such as Chevron, Tullow, and Cairn Energy, to explore the region despite low oil prices," Young Okunna, GlobalData's upstream analyst covering sub-Saharah Africa, said in a note last week. (Reporting by Kissima Diagana in Nouakchott, with Caroline Valetkevitch in New York and Emma Farge in Dakar; Editing by David Holmes)