—[*1] Hughes Hubbard & Reed, LLP, New York (Seth D. Rothman of counsel), for appellants.

Kramer Levin Naftalis & Frankel, LLP, New York (Gary P. Naftalis of counsel), for respondent.

Order, Supreme Court, New York County (Barbara R. Kapnick, J.), entered April 16, 2012, which granted defendant's motion for summary judgment dismissing the complaint, unanimously affirmed, with costs.

We agree with the motion court that plaintiffs are not entitled to additional performance-based compensation under the unambiguous agreement between plaintiffs and defendant's predecessor, Sirius Satellite Radio Inc. Looking solely to the plain language used by the parties within the four corners of the agreement (see Kass v Kass, 91 NY2d 554, 566 [1998]), the disputed term "Sirius subscribers," by which plaintiffs' performance-based compensation was measured, did not include subscribers to XM Radio, a wholly owned subsidiary which defendant acquired by merger, even though the merger had been anticipated within the agreement. Concur—Gonzalez, P.J., Mazzarelli, Renwick, Richter and Gische, JJ.