The first measurement of the cross section for top-quark pair production in
pp collisions at the LHC at center-of-mass energy sqrt(s)= 7 TeV has been
performed using 3.1 {\pm} 0.3 inverse pb of data recorded by the CMS detector.
This result utilizes the final state with two isolated, highly energetic
charged leptons, large missing transverse energy, and two or more jets.
Backgrounds from Drell-Yan and non-W/Z boson production are estimated from
data. Eleven events are observed in the data with 2.1 {\pm} 1.0 events expected
from background. The measured cross section is 194 {\pm} 72 (stat.) {\pm} 24
(syst.) {\pm} 21 (lumi.) pb, consistent with next-to-leading order predictions.
