CSX Corp. last week announced its plan to consolidate the marketing and sales operations of its two major rail units, Jacksonville-based Seaboard System Railroad and Cleveland-based Chessie System Railroads.

The Richmond-based transportation holding company, formed in 1980 by the combination of the two lines, named seven officials to direct marketing efforts along commodity and industry lines.

Consolidation of marketing for the two railroads will be directed by James A. Hagen, who was appointed executive vice president for marketing in March. Hagen, widely regarded as one of the industry's marketing masters, was formerly senior vice president of Conrail and was one of the government-owned railroad's principal architects.

The appointments, effective Sept. 1, are:

*Alvin R. Carpenter, senior vice president, coal. Carpenter had held the same post at Chessie.

*Aden C. Adams, vice president, bulk products. He had been vice president for merchandise at Seaboard.

*W. Charles McCormack, vice president, manufactured products. He was formerly vice president for marketing and planning at Seaboard.

*Donald P. Connor, vice president, sales. He was previously vice president involved in special projects for Chessie's president.

*Malcolm S. Sanders, vice president, intermodal. Sanders was recently recruited by Hagen from Conrail, where he had been assistant vice president in the boxcar and intermodal business group.

*Gerald K. Davies, vice president, marketing services. He had been assistant vice president for marketing at Chessie.

*Frederic W. Yocum Jr., vice president, equipment and customer service. He was formerly vice president and special assistant to Chessie's president.

Consolidating marketing operations has "obvious efficiencies" for the intermodal transportation company, a spokesman said. Under the new arrangement, a single national account executive will be able to provide customers with any combination of CSX's surface tranportation modes -- rail, barge and truck. CSX operates a barge company, American Commercial Lines, and a trucking concern, CMX, which, combined with rail service, cover 48 states.