* Announces deals worth around $3.4 billion over three days
* Kosmos deal includes stake in giant gas find offshoreMauritania
* Tops up reserves depleted by energy sales
LONDON, Dec 19 (Reuters) - BP on Monday agreed to buystakes in gas-heavy exploration areas off the coast ofMauritania and Senegal from Kosmos, days afterannouncing the long-awaited renewal of an onshore oil concessionin Abu Dhabi.
The combined deals are worth around $3.4 billion and willadd valuable oil and gas reserves to BP's books that have seenresources shrink on the back of divestments it needed to make topay for the 2010 Gulf of Mexico oil spill.
They follow BP's purchase of a stake in Eni's giant Zohr gasfield offshore Egypt for $375 million last month and come at atime of rising oil prices.
BP said on Monday it had agreed to buy a 62 percent stakeand operational control of Kosmos' Mauritania explorationblocks, which include the Tortue discovery, estimated by Kosmosto contain more than 15 trillion cubic feet (tcf) of gas.
In comparison, Eni's Zohr field, the largest discovery evermade in the Mediterranean, is estimated to contain 30 tcf.
Gas from the Tortue field is set to be exported from aliquefied natural gas (LNG) facility, giving BP an opportunityto grow in a highly competitive sector in which rival Shell took the lead earlier this year with the $54 billionacquisition of BG Group.
BP also agreed to buy a 32.5 percent stake in Kosmos'Senegal blocks, spending in total around $1 billion on theKosmos deal. Kosmos is a Dallas-based energy company.
"We believe the basin will become an important profit centerfor our upstream business," said Bernard Looney, chief executiveof BP's upstream business.
On Saturday, BP closed the renewal of a 40-year-longparticipation in the Abu Dhabi Company for Onshore PetroleumOperations (ADCO) after two years of negotiations, taking a 10percent stake in return for a roughly 2 percent share in BP.
The concessions included in the deal have total resources of20-30 billion barrels of oil equivalent.
"BP's shopping spree is the company's response to what theinvestor community has long been concerned about: long-termgrowth and resource sustenance," said Brendan Warn, analyst atBMO Capital Markets, who has an "Outperform" rating on thestock.
"BP's timing might have also been triggered by what it seesas a likely recovery in the oil price and asset values over2017."
Oil prices have climbed above $50 a barrel in recent weeksas the world's biggest oil producers have agreed to reduceoutput to stem global oversupply.
Shares in BP were up 0.6 percent at 1027 GMT, outperformingthe oil and gas companies index, which was down 0.15percent.
(Reporting by Karolin Schaps; Editing by Keith Weir)