PCT No. PCT/GB93/02218 Sec. 371 Date May 9, 1994 Sec. 102(e) Date May 9, 1994 PCT Filed Oct. 29, 1993 PCT Pub. No. WO94/10270 PCT Pub. Date May 11, 1994A corrosion inhibiting lubricating composition comprises: (a) a synthetic ester base stock; (b) at least one aromatic amine antioxidant; (c) a neutral organic phosphate of the formula (R1O)3 PO where R1 is a tolyl, phenyl, xylyl, alkyl or cycloalkyl group, the alkyl or cycloalkyl group having up to 10 carbon atoms; (d) a saturated or unsaturated dicarboxylic acid of the general formula to 22 inclusive and where at least one of the groups R1 to R5 is a carboxylic acid group; or a dicarboxylic acid of one of the three formulae (e) a straight or branched chain saturated or unsaturated monocarboxylic acid which is optionally sulphurised or an ester of such an acid; and (f) a triazole of the formula: or a triazole selected from 1,2,4 triazole, 1,2,3 triazole, 5-anilo-1,2,3,4-thiatriazole, 3-amino-1,2,4 triazole, 1-H-benzotriazole-1-yl-methylisocyanide, methylene-bis-benzotriazole and naphthotriazole.