Diego della Valle. Photo : Corbis

CHICAGO, Oct 21 (Reuters) - Italian businessman Diego Della Valle has boosted his stake in luxury department store operator Saks Inc (SKS.N) to just above 19 percent, becoming the company's largest shareholder and sending its shares to a two-year high.

Della Valle, the founder of Saks supplier Tod's SpA (TOD.MI), said in a regulatory filing that he now holds 22.65 million shares. In the period Oct. 12-21, he bought 7.65 million shares, according to the filing.

Della Valle and a Saks spokeswoman were not immediately available to comment.

Della Valle's latest purchases push him ahead of Mexican billionaire Carlos Slim as Saks' top shareholder.

Nearly 11 months ago, Saks removed a "poison pill" aimed at averting a potential hostile takeover by Slim, who rapidly raised his stake in the company when the shares fell below $3 in November 2008 during the global financial crisis.

Slim held a 15.9 percent stake in Saks, according to an SEC filing earlier this year.

Della Valle bought 2.9 million shares Oct. 12-18 for $29.3 million, including commissions, the filing said.

On Tuesday, he bought an additional 2.5 million shares for $27 million, and on Thursday, he bought 2.25 million more for $24.8 million.

The shares were bought for investment purposes, the filing said.

Saks shares were up 68 cents at $10.80 in late-morning trading on the New York Stock Exchange. They rose as high as $11.00 earlier in the session.

(Reporting by Brad Dorfman, editing by Gerald E. McCormick and John Wallace)