LONDON (AP) - Bob Dudley's sudden rise to the top at BP PLC shows how the Gulf oil spill has dramatically changed the fortunes of people from local fishermen to corporate executives.

Seen as an unlikely candidate just a few months ago, Dudley is set to become the first American to lead the oil giant in its century long history. Dudley will become CEO on October 1 and try to salvage the company's reputation and investments in the United States.

On a phone call with reporters yesterday, Dudley said he understands the complexity of rebuilding BP's image and financial strength. He said BP will emerge as a slimmer but stronger company.

Dudley believes the investigation will show "individual misjudgments" by experienced people and "multiple failures" of equipment involving several companies led to the April 20 explosion on the Deepwater Horizon drilling rig.

"I think it is a very complicated industrial accident," he said.

Dudley's standing within BP and along the Gulf Coast has risen since he took over BP's response to the oil spill in June from current CEO Tony Hayward, who will remain on BP's board until November 30.

Dudley delivered BP's message — don't worry, we're going to pay for all this — in a calm manner without Hayward's public impatience and knack for off-putting comments. And serendipity was on Dudley's side: He was in charge when BP finally capped the spewing well, shutting off the flow of oil until a relief well can finish the job.

BP is the largest producer of oil and gas in the United States, home to 40 percent of the company's assets and one-third of its worldwide oil and gas reserves. It has huge interests in Alaska and the Gulf, with vast tracts yet to be developed.

Those resources could be threatened. The US Congress is considering a proposal to block the awarding of any new offshore oil and gas leases to companies with bad safety records. BP would be targeted, the way the legislation is written. BP might also lose its fuel contracts with the military, worth $2.2 billion last year.

If BP is going to survive , it must protect those assets, says Amy Myers Jaffe, an oil industry scholar at Rice University in Houston.

Dudley has adamantly defended BP's actions since the rig explosion. He must now ensure that BP pays for the oil spill, as promised. Yesterday, the company said it has set aside $32 billion to cover the costs. Dudley will oversee the sale of about $30 billion in assets over the next 18 months to ensure that BP has ample reserves of cash.

He'll need to regain the trust of shareholders, who could bail on BP if it doesn't resume dividend payments next year. Shares have dropped 36 percent — and lost $68 billion of their value — since the oil spill started. And that's after a rally since late June.

"His first job is to convince people BP is going to come back and you better buy BP stock while it's cheap," Jaffe says.

In early April, nobody thought BP would soon need a new CEO. BP earned more than $20 billion in Hayward's first two years as CEO. Even with lower oil prices in 2009, BP still made $16.6 billion.

Dudley, 54, was a longtime executive with Amoco before BP bought that company in 1998. He ran BP's joint venture in Russia for five years and lost out to Hayward for the CEO job in 2007. He then turned into a globe-trotting Mr. Fix-it for his bosses in London. It was that last role that landed him back along the Gulf, near where he grew up in Mississippi, after the April rig explosion that killed 11 men and spawned the oil gusher.

In that thread of biography lie several factors that elevated him above other candidates to replace Hayward, including Britons with years more experience inside BP, according to analysts.

"The two aspects of Dudley's work that make him an optimal candidate for CEO are that he's not Tony Hayward and he speaks with an American accent," says Pavel Molchanov, an analyst with Raymond James.