MILL VALLEY, Calif. (AP) ¿ Redwood Trust Inc., a real estate investment trust, said Tuesday it plans to offer 13 million shares of common stock. The company plans to use the proceeds to acquire residential and commercial real estate loans and mortgage securities. It may also be used to invest with third party investors in funds which Redwood Trust may sponsor, and for general corporate purposes. The bookrunning manager for the offering is J.P. Morgan Securities Inc. The underwriters will have a 30-day option to purchase up to an additional 1.95 million shares to cover over-allotments, if any. Redwood currently has about 60.3 million shares outstanding. Shares in the Mill Valley, Calif.-based company fell 32 cents, or 2 percent, to close at $15.58, and slipped 71 cents in aftermarket trading.