By Alexandra Alper and Gabriel Stargardter
RIO DE JANEIRO, Sept 28 (Reuters) - Royal Dutch Shell Plcand Chevron Corp on Friday led big bets by oilmajors seeking to clinch key stakes in Brazil's coveted offshoreoil play, shrugging off concerns over presidential electionsthat have shed uncertainty over the industry.
Shell and Chevron pledged to the government a high 70.2percent of the oil it produces after costs to clinch the choiceSaturno block, while Exxon Mobil Corp and QatarPetroleum International landed the Tita area with a 24.5 percentoffer, with both groups locking in key real estate in the prizedSantos basin.
By offering all four blocks, Brazil's cash-strappedgovernment raked in 6.82 billion reais ($1.71 billion), daysahead of the most uncertain presidential vote in a generation,as oil companies scrambled to take advantage of what could bethe last oil auction in years.
Leftist candidates have proposed slowing down oil auctions,revising market-friendly legislation or even clawing back areasalready awarded. Meanwhile, right-wing presidential front-runnerJair Bolsonaro has floated the idea of privatizing state oilfirm Petrobras and has said he would champion amarket-friendly approach.
"We take a long term view on these things," said FelipeArbelaez, chief for Latin America of BP Plc, which tookthe Santos Basin's Pau Brasil block in a consortium withColombia's Ecopetrol and China's CNOOC Ltd.
"Ultimately, we think Brazil has a long track record ofrespect of law, respect of contracts so we're not very concernedabout the elections," Arbelaez said.
Lured by world-class geology, shrinking reserves and risingoil prices, companies have already dropped billions of dollarsin Brazil, Latin America's top oil producer, to lock in stakesin its pre-salt layer, where billions of barrels of oil aretrapped under a thick layer of salt offshore.
Oil majors' interest has been boosted by industry-friendlypolicies under center-right President Michel Temer, includingloosening rules favoring local suppliers, tax sweeteners and theremoval of a requirement that Petrobras be sole operator inpre-salt blocks.
Petrobras was the sole bidder and won the Southwest ofTartaruga Verde block in the Campos Basin.($1 = 4.0235 reais)(Writing by Alexandra Alper; Additional Reporting by MartaNogueira and Rodrigo Viga Gaier Editing by Cynthia Osterman andJeffrey Benkoe)