Monopolist

(n.) One who monopolizes; one who has a monopoly; one who favors monopoly.

Thesaurus Entries

careerist, censor, egotist, fortune hunter, hog, individualist, lone wolf, loner, narcissist, protectionist, restrictionist, road hog, self-advancer, self-pleaser, self-seeker, self-server, temporizer, timepleaser, timeserver, tufthunter