Sotheby's said it would cut an unspecified number of jobs to cut cost, months after ending a long-running battle with billionaire investor Daniel Loeb by appointing him to its board.

Sotheby's shares rose 3 percent to $39 on the New York Stock Exchange on Friday.

Loeb, a prominent art collector, has long criticized Sotheby's for spending too much and not being properly positioned in the modern art market.

Loeb runs Third Point, Sotheby's biggest shareholder with a stake of 9.7 percent as of May.

The auction house, which has reported a loss for five of the last nine quarters, said on Friday it expects employee-related restructuring charges of about $13 million in the current quarter.

The job cuts, mainly impacting the company's U.S. and UK operations, are expected to be fully implemented by the end of the year, Sotheby's said.

Sotheby's had 1,577 employees as of Dec. 31, 2013, with 618 in North America and South America, and 521 in the UK.

The restructuring plan, the result of a strategic review, will result in the reallocation of resources to collecting categories and regions with the highest growth opportunity, the company said.