Looking at this on the ITA tool (I'm assuming the OP is travelling in Business class based on the mention of the LAX-SIN nonstop):
There doesn't appear to be a CO NYC-SIN fare that lets you travel EWR-LAX on CO and then onwards on SQ. However the SQ fare SIN-NYC does allow the LAX-EWR portion on CO. The way ITA prices it is as follows:
CO EWRLAX BCOUPP fare $761.86
SQ LAXSIN DSPCL $2651.50
SQ SINNYC JMPA NUC 4102.02
The total fare is $8,026 round trip.
Originally Posted by
snod08
I think SQ has these options (please correct me if I am wrong) from EWR and LAX.,
EWR-SIN = All business class A345
LAX - SIN = All business class A345
LAX-NRT-SIN = 747 with 3-classes of service.
This is correct.