Simulations Plus on Tuesday announced a registered public offering of its shares in order to pursue a possible merger or acquisition. Existing stock fell in price. The Lancaster drug modeling software company did not disclose how many shares it hopes to sell or how much money it hopes to raise as a result of the offering and was quick to add that it presently has no commitments or agreements to enter into an M&A with a specific company. Simulations Plus expects to grant the underwriters of the offering a 30-day option to purchase additional shares, the company said in a statement. “The offering is subject to market and other conditions, and there can be no assurance as to whether or when the offering may be completed, or as to the actual size or terms of the offering,” the company said. Oppenheimer & Co. Inc. and Raymond James & Associates Inc. are joint book-running managers for the offering, Simulations added in its statement. Shares of Simulations Plus (SLP) closed down $3.65, or more than 5 percent, to $68.44 on the Nasdaq on Tuesday, a day when the major exchanges closed up less than 1 percent.