Yes, one of the many strategies that LTCM used was pairs trading.Quote from MathAndLogic:
As an aside, LTCM pairs-traded. Not sure if with options. They blew up. Comments?
As MTE mentioned, it was their extreme debt to asset leverage that was their downfall. It was something like 30:1 before the Russian bond defaults eroded their equity and forced them to unwind positions prematurely.