if a broker doesn't list a cross, is valid to trade the majors that form the pair?

or, the spread is bigger trading the cross. For example, GBPCHF. If my broker has a pread of 12 pips on it is a good idea to buy GU and sell USDCHF?

thanks in advance.

There was some discussion on this here>> http://www.forexfactory.com/showthread.php?t=201792

I just want to know how to make that a clickable link so the word "here" is blue and underlined !!

Anyway, see if that thread has some answers for you.

Yes, check out the link in the previous post. You will have to adjust your position sizes to get equal exposure. And, you'd be using more margin.

many thanks