Officials at Rubio’s Restaurants, Inc. (NASDAQ: RUBO), a company that started as a simple walk-up taco stand on East Mission Bay Drive in 1983, announced May 10 that the company has entered into a merger agreement with private investment firm Mill Road Capital for $91 million. Founder and San Diego native Ralph Rubio, who started the company with his father, grew the business from a one-stop taco shop to a thriving restaurant chain with more than 180 locations in the western half of the United States. Under the agreement, Mill Road will buy all the outstanding shares of common stock of Rubio’s Restaurants for $8.70 a share, a 14 percent premium over the closing share price of Rubio’s common stock on May 7, according to company officials. Ralph Rubio, Rosewood Capital and Rubio’s president and CEO Daniel Pittard collectively own 24 percent of those outstanding shares. Mill Road currently owns 4.9 percent of the company. “Rubio’s is a long-established institution in its core western markets with a consistent track record of providing delicious Baja-inspired food to its large base of loyal customers. As a long-term shareholder, Mill Road Capital is delighted to have the opportunity to increase its investment in the great institution that Ralph Rubio created 27 years ago and to work with Dan Pittard and his talented team in executing their strategic plan and building an even greater Rubio’s,” said Scott Scharfman, Mill Road’s managing director, in a prepared statement. The merger is still subject to approval by regulators and Rubio’s stockholders, as well as other customary closing conditions, but it is expected to close in the third quarter of 2010, officials said. According to Mill Road’s website, the company specializes in investments in publicly-traded companies valued at less than $250 million. Mill Road’s portfolio already includes businesses in retail, manufacturing, business services and consumer products. Representatives from Rubio’s were not immediately available for comment regarding what impact the buyout may have on the Carlsbad-based operations or the individual restaurant locations.