Does a large effective population size result in faster decay of linkage disequilibrium (LD)?
It is certainly possible as yes, rapid population growth will reduce LD.  From Slatkin, 1994:


  In a rapidly growing population, however, there will be little chance of finding significant nonrandom associations even between completely linked loci if the growth has been sufficiently rapid.


Or Nature Reviews, 2002


  Przeworski... showed that population growth tends to decrease the extent of LD, especially for longer periods of growth. By contrast, population subdivision tends to increase the extent of LD, especially when a sample contains individuals from several strongly differentiated subpopulations.


See also box 1:


  Rapid population growth decreases LD by reducing genetic drift.