Sotheby's Inc. has approved a restructuring plan that will lead to salary reductions and layoffs because of poorer than expected earnings.

It was unclear how many people would lose their jobs. The art and antiques auction house said Friday that the plan would affect its North American operations, which employs 605 people.

Its rival, Christie's, said Friday that it, too, was reviewing its strategic plan due to the global financial crisis and its sales results for the fall.

"We are considering reorganization which would lead to layoffs," said spokesman Toby Usnik. The company has 2,100 full-time employees worldwide.

In a Thursday filing with the Securities and Exchange Commission, Sotheby's said that it would take a $5 million charge against earning in the fourth quarter related to employee restructuring. Beginning in 2009, the restructuring plan "will reduce annual salaries and related costs by approximately $7 million, when compared to 2008 levels."

Unlike Sotheby's, Christie's is a privately held company and as such is not required to disclose its financials.

However, Usnik said, "We are on solid financial footing but like all businesses, we're reviewing our business strategies in light of the current global economic environment."

More details will be announced in early January, he said.

The auction houses' important sales of contemporary, modern and impressionist art last month were the first strong indicators of a slowdown in the fine art market. Many works went unsold and many others sold at or below their estimates.

Afterward, Sotheby's chief executive Bill Ruprecht conceded that the global financial meltdown had an impact on its sales, but predicted that going forward the company would "be meaningfully profitable at significantly lower sales levels."

Sotheby's shares rose 34 cents, or 3.9 percent, to close at $9.06 Friday. The stock is still down 76 percent this year. Its 52-week range has been $7.24 to $39.67.