Weighing in with its influential voting recommendations, proxy advisory firm Institutional Shareholder Services (ISS) on Thursday gave activist investor Daniel Loeb a boost in his battle with the management of auction house Sotheby’s.

As The New York Times reported, ISS recommended that Sotheby’s shareholders vote for two of the three candidates that Loeb has recommended for election to the company’s board of directors.

ISS “ultimately concluded,” the Times reported, “that two of Mr. Loeb’s nominees, himself and Olivier Reza, a former investment banker, would be of great benefit to Sotheby’s because both are active art collectors, unlike the candidates put up by the company.”

The third nominee, whom ISS did not recommend, is Harry Wilson. As the Times noted, Wilson is a restructuring expert who has served with Loeb on Yahoo’s board.

In its report, according to the Times, ISS wrote that “Loeb had made a ‘compelling’ case that the company had underperformed financially. Its operating expenses, the Times noted, have taken a larger and larger chunk out of sales over the past three years, and last year touched 74 percent of revenue.

While ISS—which, according to its website, has 1700 clients, most of then large institutional investors—supported Loeb, its smaller rival Glass Lewis, has thrown its support behind the auction house’s slate of directors and viewpoint, the Times reported.

According to the Times, a report produced by Glass Lewis read: “While we believe Mr. Loeb could still add value as a director, we don’t think he and his firm have made a strong enough case that the board is in need of further change at this point, or that his appointment would improve the board to such an extent that would justify his election in place of a management nominee.”

The Times reported that Sotheby’s issued the following statement in response to the ISS recommendation: “Now is not the time to diverge from Sotheby’s leadership and its strategic plan. We believe that replacing any of Sotheby’s director nominees with Mr. Loeb or any of his handpicked nominees could negatively impact shareholder value.”

Loeb’s Third Point hedge fund countered that “To dismiss ISS’s well-reasoned, respected analysis out-of- hand either shows that this board is in complete denial or demonstrates a cognitive dissonance which alone should convince shareholders to support Third Point’s nominees.”

Sotheby’s annual meeting is scheduled for May 6.