Except as stated in Section 698, one who, without a privilege to do so, induces or otherwise purposely causes a third person not to
(a) perform a contract with another, or
(b) enter into or continue a business relation with another
is liable to the other for the harm caused thereby.
REST TORTS § 766
One who intentionally and improperly interferes with another’s prospective contractual relation (except a contract to marry) is subject to liability to the other for the pecuniary harm resulting from loss of the benefits of the relation, whether the interference consists of
(a) inducing or otherwise causing a third person not to enter into or continue the prospective relation or
(b) preventing the other from acquiring or continuing the prospective relation.
REST 2d TORTS § 766B