Residential group Grainger has reached an agreement to sell its stake in the New Sovereign Reversions Ltd portfolio for £18.5m.The London-listed company will sell its 50% interest in the portfolio, a joint venture with Moorfield Real Estate Fund II, to an affiliate of private equity group Lone Star Funds.The FTSE 250 group said expected to make a £4.5m pre-tax profit on the sale."We are pleased to announce today's sale which was a compelling opportunity to realise an attractive return on our investment and support our joint venture partner's wider strategic activity," said group chief executive Andrew Cunningham.Grainger shares were down 0.05% to 211.70p.