Barry Covington in front of Covington Buick in Silver Spring, and Steven Brodoll, right, helping A1 Showalter at Anacostia Chrysler Plymouth.</br></br>Citizens & Southern National Bank in Atlanta, one of the South?Ûªs biggest banks, secretly financed the acquis-tion of 25 Georgia banks by officers, directors and friendly associates of the bank, according to a civil suit filed yesterday by the Securities and Exchange Commissions.</br></br>The SEC accused the bank of violating federal securities laws by failing to make full disclosure to its stockholders of the terms of the acquisitions.</br></br>The suit, filed in U.S. District Court in Atlanta, said that six of those 25 banks, located near Atlanta, were acquired by C&S in 1975 and that the terms were negotiated by bank officials who were shareholders of the ac-quired bflnks</br></br>The C&S officials and friends of the bank were financed in the acquisition of the so-called ?ÛÏcorrespondent associate banks?Û? by C&S loans featuring preferential interest rates and non-payment of principal, the SEC said.