Orchid Island Capital, a firm that invests in residential mortgage-backed securities, postponed a planned 5.2 million-share public offering on Monday, according to Renaissance Capital. The delay comes five days after Orchid Island announced it would be lowering the size of its IPO. By going public, Orchid Island could achieve the status of a real estate investment trust, which would allow for certain tax benefits, but limit investments to the mortgage finance space. As of last week, plans were still on for the Vero Beach, Fla.-based company to raise $42 million by offering 5.2 million shares for $8 each. Earlier proposals suggested the firm would offer 7.5 million shares at a range of $10 to $12 per share, but Orchid later lowered its proposed offering. As a REIT, Orchid would aim to invest heavily in Fannie Mae, Freddie Mac and Ginnie Mae mortgage-backed securities. Write to Kerri Panchuk. ?