Abstract: A new class of hydrocarbon-soluble sulfur-free oxymolybdenum compounds is described having the formula[(RO).sub.n (HO).sub.3-n PO](MoO.sub.3).sub.xwhere n=1 to 2; x=more than 1 to 9 except when n=2, then x=not more than 6 and when n=1.5 then x is not more than 7.5. The R radical is defined as substantially hydrocarbyl and may be alkyl, substituted alkyl, aryl, aralkyl, cycloalkyl or alkaryl. The compounds are prepared by the reaction of monoalkyl or dialkyl acid phosphates or mixtures thereof with molybdic oxide suspended in a suitable medium, together with a catalytic amount of a basic material such as an alkali metal hydroxide or hydrosulfide. Lubricant compositions containing these novel compounds are also described.