Sears, Roebuck and Co. appointed Everett L. Buckardt as executive vice president, catalog and direct marketing, and Marvin M. Stern as vice president, home appliances and home entertainment, for Sears Merchandise Group effective April 1.

Edward A. Brennan, chairman and chief executive officer of Sears, Roebuck, said the board of directors will be asked to elect Mr. Buckardt and Mr. Stern to their new positions at its next scheduled meeting.In his newly created position, Mr. Buckardt will be responsible for all catalog sales, direct mail and electronic marketing. He will create the organization necessary for a differentiated catalog and direct marketing business, said Michael Bozic, chairman and chief executive officer of Sears Merchandise Group.

Mr. Buckardt will report directly to Mr. Bozic in his new post.

This will allow us to focus on Sears competitive advantages in marketing directly to the diverse and changing lifestyles of the American consumer, Mr. Bozic said.

Mr. Buckardt, 54, has been vice president, operating, since July 1, 1986. He joined Sears in 1959 as a management trainee and has held a number of executive positions in the Midwest and East.

Mr. Stern, 52, succeeds Matthew A. Howard, who last week was named senior executive vice president, merchandising. Mr. Stern will report to Mr. Howard in his new post.

A 22-year veteran of Sears, Mr. Stern left the company in 1981 and served several years as a merchandising officer of Montgomery Ward.

After leaving Montgomery Ward, he became a management consultant.

From 1974 to 1981, Mr. Stern progressed through a number of national merchandise manager assignments with Sears.

BANFI VINTNERS (Old Brookville, N.Y.) - Lars Leicht was appointed brand manager, world class wines. He succeeds Virginia Mariani Foster, who has taken maternity leave.

In his new position, Mr. Leicht will coordinate national marketing efforts behind such brands as Principessa Gavi, Banfi Brut (methode champenoise), Fontanelle Chardonnay, Banfi Brunello di Montalcino and Tavernelle Cabernet Sauvignon.

Mr. Leicht joined Banfi in 1986 as a sales representative in New York, covering northern Westchester County.