Executives at Imperial Credit Commercial Mortgage Investment Corp., a troubled commercial mortgage lender, said they have accepted an offer to sell the real estate investment trust for $11.50 a share. The price--criticized as too low by some shareholders--represents a 17% premium to Imperial Credit Commercial's stock price on May 12, the day before the offer was originally announced. But it remains below the company's book value of $14 a share. The REIT's stock closed at $10.88, up 13 cents on Nasdaq. The proposed buyer is Torrance-based Imperial Credit Industries Inc., which manages the REIT and already owns a 10% stake. The companies said they expect the deal--subject to shareholder approval--to close by the end of the year. Imperial Credit Commercial can continue to explore more favorable offers, but another buyer would face a potential $35-million termination fee to buy off the management contract on the REIT. At a shareholder meeting last month, Imperial Credit Commercial investors complained that the company was using the management contract to scare away potential buyers and force REIT shareholders to accept a low offer.