BP shareholders are fleeing the company’s stock amid growing uncertainty about the ultimate bill for cleanup costs, lawsuits, fines and damage to the oil giant’s reputation.

BP’s shares fell an additional 15 percent on Tuesday, as investors reacted to news that the latest effort to stem the gushing oil in the Gulf of Mexico failed over the weekend. It is the steepest drop in shares in about two decades.

Also on Tuesday, Attorney General Eric H. Holder Jr. said that federal authorities had opened criminal and civil investigations into the Deepwater Horizon explosion.

Since the Deepwater Horizon drilling rig exploded April 20, the company has lost a third of its market value, or about $75 billion.

The company said Tuesday that it had spent almost $1 billion on cleanup efforts. But that bill is likely to rise as oil continues to spill into the gulf, with no guarantees that any of the new plans to contain the spill will work.

Investors are also grappling with potential damage to the company’s reputation.

“Financially they can survive this crisis, but politically they will be punished for a very long time,” said Fadel Gheit, an oil analyst at Oppenheimer & Company.

The prospect of billions of dollars more in legal payouts and fines is also weighing on the company.

BP officials say they have already paid $36 million to settle claims of economic loss and damage under the Oil Pollution Act, a 1990 law passed in the wake of the Exxon Valdez disaster, and that more than 26,000 claims have been submitted.

Microsoft Corp. sued Salesforce.com Inc. yesterday, accusing the company of infringing nine patents for ways to make software more efficient.

The complaint targets the customer-relationship management software that is the hallmark of Salesforce.com’s business. It seeks a court order that would prevent the San Francisco-based company from providing features that Microsoft claims it invented.

Salesforce.com, founded in 1999, sells subscriptions to Internet business software that runs marketing campaigns and tracks sales leads. It competes against Microsoft’s Dynamics programs and “has profited through infringement of the Microsoft patents-in-suit,” according to the complaint, filed in federal court in Seattle.

“More and more, we’re seeing Dynamics compete with Salesforce in deals,” said Ray Wang, an analyst with Altimeter Group in San Mateo, California. “Long term, Salesforce and Microsoft are on a collision course for all enterprise software.”

Movie Gallery Inc., the owner of struggling movie rental chain Hollywood Video, is planning to close its remaining stores and liquidate as consumers are increasingly get movies through the mail, vending machines and high-speed Internet connections.

The No. 2 rental chain behind Blockbuster Inc. filed a notice with the U.S. Bankruptcy Court for the Eastern District of Virginia in Richmond late last week that it will terminate its business operations after defaulting on a loan from one of its creditors.

An agreement filed with the court sais the move to close more than 1,900 remaining stores is in the "best interests" of the company and its creditors. The agreement does not specify a time line. It must be approved by a bankruptcy judge.

Phone calls to Movie Gallery and an attorney representing the company were not immediately returned.

The company, based in Wilsonville, Ore., filed for Chapter 11 bankruptcy in February, buckling under the competitive pressure from movies-by-mail service Netflix Inc., DVD kiosk company Redbox and delivery of movies and TV shows over the Internet.

Former Qwest Communications International Inc. CEO Joe Nacchio is set to appear in federal court in Denver to say whether he wants to waive his right to attend his re-sentencing hearings.

U.S. District Judge Marcia Krieger wants to see Nacchio in person Tuesday before allowing him to skip hearings in June where she will recalculate his sentence for insider trading convictions.

An appeals court ruled that Nacchio's original sentence of six years in prison, plus $71 million in fines and forfeitures, was too harsh.

Nacchio has started serving his sentence at a prison in Pennsylvania. Online federal prison records show he was moved to a low-security facility in Englewood, Colo., before the hearing Tuesday.

Lorillard, the maker of Newport, Maverick and True cigarettes, says its first-quarter profit climbed 26 percent as domestic wholesale shipments and average prices grew.

The nation's third-biggest cigarette maker said higher federal excise taxes on smokes helped boost its revenue.

Lorillard said Monday its earnings rose to $232 million, or $1.50 per share, in the three months ended March 31. That's up from earnings of $184 million, or $1.09 a share, a year ago.

It says revenue climbed to $1.36 billion from $917 million as domestic wholesale shipments of discount brand Maverick grew 48.7 percent. Excluding federal excise taxes, revenue was $923 million partly on higher average prices. Wall Street predicted revenue of $802.7 million.

The Supreme Court is stepping into a legal fight over Omega's effort to stop Costco from offering the Swiss maker's watches for up to a third less than they cost elsewhere.

The case has important implications for discount sellers like Costco and Target as well as eBay, Amazon and other companies that form an estimated $58 billion annual market for goods that are purchased abroad, then imported and resold without the permission of the manufacturer.

The justices said Monday they will hear Costco's appeal of a lower court ruling that sided with Omega in its attempt to invoke U.S. copyright law to halt the discount sales. Omega owns a U.S. copyright on the Omega Globe Design symbol that is engraved on its watches at the time they are made.

The high court has previously ruled that copyright protections do not apply to goods made in the United States, sold abroad and then imported back into the country for resale. At issue in this case are items that are manufactured overseas, sold by their maker abroad and then brought back here for resale.

This means of purchase, importation and resale is sometimes called the secondary-goods or gray-goods market, and it is a big part of Costco's business.