Robert E. Dewar, 77, former top executive of Kmart who led the expansion of the chain in the 1970s. Dewar was chairman and chief executive of the Troy, Mich.-based discount retailer. With a law degree from Wayne State University, he joined S.S. Kresge, the company that became Kmart, as an attorney in its legal department in 1948. Appointed president and chief administrative officer in 1970 and chairman of the board and chief executive in 1972, he dropped the Kresge name in favor of Kmart in 1977, when it became the nation's third-largest retailer after Sears and Safeway. Dewar oversaw the rapid growth of the company during the 1970s, opening 271 Kmart outlets in 1976 alone--an unprecedented feat in retail history, according to Fortune magazine. Between 1970 and 1980, Kmart opened more than 1,000 stores in all and increased sales from $2.5 billion to $14.2 billion. Dewar stepped down as chairman in 1980 when the company faced declining earnings but remained on the board for several years, retiring in 1988. He served as chairman of the Michigan Opera Theatre, raising more than $18 million to establish a new opera house. On Thursday of complications from colon cancer at his home in Bloomfield Hills, Mich.