(ShareCast News) - Shares in Origo Partners plunged 15% after Brooks Macdonald Asset Management said it has filed a claim against it over a clause in the company's Articles of Association related to the conversion of preference shares.It said it hopes that a consensual resolution can be reached with Origo on this matter.Origo Partners confirmed later on Tuesday that Brooks Macdonald had notified the company of a claim and said it was giving "serious consideration" to the concern raised by Brooks.Origo said it remains committed to attempting to work with Brooks to achieve a mutually-acceptable resolution.