A PRIVATE investor has paid about £600,000 for a retail and office investment occupied by Stena Line at 15 Westmoreland Street, Dublin 2. The investment will produce a yield of 6.75 per cent. Hamilton Osborne King handled the sale for a pension fund in Independent Newspapers. Liam Lenehan, of the selling agents, would not confirm the price paid but said the yield was one of the lowest for an investment in a secondary shopping street. The strong selling price underlines the severe shortage of good investments in the city centre. Hamilton Osborne King originally sought around £525,000 for the building and eventually sold it by private tender because of the high level of interest in it. The building, which has a total of 3,300 square feet, is let on a 35-year full repairing and insuring lease with no break clauses. The lease does not expire for another 27 years. Stena is the main ferry company operating out of this country.