By Tom Hals

NEW ORLEANS, (Reuters) - Scores of attorneys willjam a federal courtroom Thursday to argue for almostimmediate access to emails and other documents from BP Plc and its business partners as the legal fight overthe Gulf of Mexico oil spill heats up.

The hearing is the first major gathering of attorneysinvolved in the sprawling spill-related litigation sincehundreds of civil lawsuits were combined before a judge in NewOrleans federal court last month.

The lawsuits, brought by shrimpers, injured rig workers,property owners and others, will get an initial airing at thehearing with an expected fight over the pace of the case.

The stakes are huge. Some legal consultants have estimatedthe total cost to BP and its co-defendants from the biggest oilspill in U.S. history to BP could run to $100 billion ifmaximum fines and punitive damages are assessed.

BP has taken a one-time charge of about $32 billion toreflect the estimated costs of lawsuits, claims and fines fromthe spill.

The lawsuits against BP, as well as Transocean Ltdand Halliburton Co, are expected to drag on for years.The defendants are expected to argue at Thursday's hearing thatmost individuals and businesses who are suing do not have aright to be in court, based on the briefs they filed.

The defendants will argue that they should not turn overlarge volumes of potential evidence until next year after thecourt determines who can sue.

If the judge, Carl Barbier, opts for an acceleratedschedule, it would allow plaintiffs' attorneys to quickly buildtheir case before their clients feel pressed to settle.

For the defense, a slower pace will give time for claims tobe paid from a $20 billion fund set up by BP, which is beingoverseen by the Obama administration's former executive payczar, Kenneth Feinberg.

Each individual or business who accepts a final payment ontheir claim gives up the right to sue BP, and presumably thestrongest legal cases will fall away as the payments flow.

"Defendants want to delay substantive progress for six toeight months, see what has occurred in the BP Claims Facility,and then, perhaps, commence the litigation," the plaintiffs'attorneys wrote in a court filing.

If the judge accepts the plaintiffs proposed schedule, theyexpect by March to have a list of cases to try. The defendantspreferred to take up the issue of the "appropriateness" of testtrials next year, without offering a time frame.

LOST PIZZA SALES

The hearing will attract some of the Gulf region'sbest-known plaintiff's firms and lawyers who have racked upbillions in settlements with drug companies and tobacco firms.

Lawsuits have been filed by heavyweights of the plaintiffs'bar, including Texas attorney Mark Lanier and ElizabethCabraser, a California lawyer.

The cases have ranged from commercial fisherman who lost anentire season of catches to Post Corner Pizza in farawayClearwater, Florida, which said sales were "eviscerated" by thespill. The local tourism board says the city was unaffected.

Many restaurants such as the famed Bayona in New Orleansargued they were indirectly harmed by the lack of fresh seafoodfrom the Gulf. Feinberg will have determine who gets a payout.

"How far down the chain do you go? That's the toughest ofthe tough issues here," said Scott Giordano, the corporatetechnology counsel for Mitratech Inc, which provides legalconsulting and technology.

Alleged victims have three years to submit a claim toFeinberg, and BP and its defendants said this week only thosewho have had a claim rejected by Feinberg's fund have a rightto sue.

The more claims Feinberg settles, the fewer lawsuits thatare brought, and less likely that the defendants are hit withpunitive damages, which are trickier and more time-consuming toprove but would open the door to massive payouts.

"I doubt (claimants) would hold out for punitive damages.That's the ace in the hole that Feinberg has," said Ed Sherman,a law professor with Tulane University Law School in NewOrleans.

James Roy, a Louisiana attorney who is co-liaison counselfor the plaintiffs, said he doubts BP will be able to cover allthe claims with its Feinberg fund, but doesn't expect it to runas high as $100 billion.

"It will be expensive to litigate and time-consuming," hesaid. "Will it take as long as the Exxon Valdez (spill case)?No. Will it last 10 years? No. Will it be in the three- tofive-year time frame? I hope so."

The case is In re Oil Spill by the Oil Rig "DeepwaterHorizon" in the Gulf of Mexico April 20, 2010, U.S. DistrictCourt, Eastern District of Louisiana, No. 10-MDL-2179. (Reporting by Tom Hals. Editing by Robert MacMillan)