Activist investor Engine Capital said in its third-quarter letter to investors that MRC Global Inc. (NYSE:MRC) is "deeply undervalued" and is urging the pipe, valves and fittings distributor to consider exploring a sale, according to Bloomberg News' Crystal Tse. Engine Capital, which has about a 4% stake in MRC Global, said it believes the company could get $14 to $18 per share in a potential sale, the report said.