Colby's longest-serving president, Bill Cotter, who capitalized on the College's strengths to cement Colby's status among the upper ranks of America's private liberal arts colleges, announced in January that he will retire next year. A committee to select his successor already has been assembled.     Cotter was 44 years old when he assumed Colby's presidency in 1979. When he retires on June 30, 2000, he will have served 21 years. That's two years longer than the previous longest-serving presidents, Robert E. Lee Strider II (1960-79) and Arthur Jeremiah Roberts (1908-1927). It continues Colby's tradition of stability in the president's office--there will have been only six presidents during the 20th century, and the last five will have averaged 18 years of service.     Under Cotter's leadership, the College increased its endowment from $25 million to $242 million (at the end of the last fiscal year), constructed or substantially expanded more than 20 buildings, added more than 30 endowed faculty chairs, expanded efforts to increase diversity on campus and saw record numbers of students participate in international study programs.     Larry Pugh '56, chair of the Board of Trustees, said Cotter will leave an extraordinary legacy. "This is, of course, sad news for Colby as he has provided such excellent leadership for the College," Pugh said. "At the same time, it is a time to celebrate all that he has done to position Colby so strongly and prominently in higher education, to celebrate the great promise the College shows for the next century and, not least, to celebrate his and Linda's well-deserved retirement."     "Colby has been our life for the past twenty years," Cotter said. "We are grateful for every friendship and for all that the College has been able to achieve thanks to our community's unusual dedication. Because of its many strengths, I know that the College will attract a number of fine candidates for the next presidency."     Pugh, who retires later this year as board chair (see page 22), and his successor, Jim Crawford '64, announced on February 22 that a 19-member committee will lead the search for a new president. In addition to Pugh and Crawford, the committee includes trustees Joseph Boulos '68, Susan Comeau '63, Gerald Holtz '52, Colleen Khoury '64, Edson Mitchell '75, Paul Schupf and Anne O'Hanian Szostak '72; faculty members Jill Gordon (philosophy), Jim Meehan (economics), Shelby Nelson (physics), Tom Tietenberg (economics) and Cedric Bryant (English); students Anthony Frangie '01 and Erin Roberts '00; Dean of the College Earl Smith and Director of Personnel Services Doug Terp '84; and Joanne Weddell Magyar '71, chair of the Alumni Council.     The committee hopes to present a final candidate or candidates for consideration by the Board of Trustees at the board's January 2000 meeting.