Advisory and asset management River and Mercantile Group said it will manage a £700m options mandate for the Royal Mail Pension Plan.The group said it was appointed by FTSE 100-listed Royal Mail in April, with the structure of the mandate designed and delivered last month."This is a very significant appointment for R&M and highlights the tangible benefits of using structured equity to manage equity risks," said James Barham, River and Mercantile's global head of distribution.Barham added that the group continued to see strong demand from pension funds and other institutions for structured equity."The design and execution of the Royal Mail mandate demonstrates the group's ability to design innovative, outcome oriented solutions for our clients, which are delivered to meet their governance requirements," Barham said.As of 11:20 on Monday, River and Mercantile Group shares were up 4.05% to 218.50p, while Royal Mail shares were down 0.13% to 506.35p.