The headline on a story about Telenet Corp. in yesterday's editions was incorrect. As the story said, Anthony A. Barnett has resigned as president and a director. He wwas not chairman as the headline stated.

Anthony A. Barnett resigned yesterday as president and director of Telenet Corp., a young, Vienna-based communications firm that provides data services for government and business.

Barnett's sudden decision came in the wake of reports that Telenet has held preliminary negotiations with "a major corporation" about a possible acquisition or merger involving the Northern Virginia company.

But, in a telephone interview last night, Barnett said his resignation is not related to the negotiations.

The 47-year-old Barnett said he resigned to pursue other interests but he declined to be specific. "We still have friendly relationships," he said of Telenet.

Lawrence Roberts, 39. founder and chairman of Telenet, will assume the role of acting president and the company will undertake a search for an executive to replace Barnett, Telenet said in a brief announcement.

Roberts was not available to comment on yesterday's developments, which followed a Telenet board meeting on Tuesday.

On Sept. 15, Telenet had revealed the talks with another company but spokesmen have declined to identify the potential suitor. The discussions haven't concluded and no offer has been made, nor is it known if any is forthcoming," a spokesman said.

Telenet went public last year with a sale of 625,000 shares to the public and the company's stock advanced sharply in heavy trading during the week before potential merger talks were disclosed. After trading at about $15 a share, Telenet jumped to $21. Yesterday, the stock was quoted at $20.25 before Barnett's resignation but it declined thereafter and closed at $19.50, down 25 cents for the day.

Because of expected startup costs and initial investments in facilities, Telenet has not yet reported a profitable period in business. In the first six months of 1978, the firm had a loss of $2.4 million on revenues of $3.6 million compared with a year-earlier loss of $1.9 million on sales of $1.6 million.

Barnett had been associated with the Bunker Ramo Corp. for 14 years until he was named president of Telenet in March 1977. At Bunker Kamo, he was senior vice president and headed an information systems group. He was instrumental in developing a central computerized market for over-the-counter stocks - the well-known NASDAQ system used by the National Association of Securities Dealers.

Roberts was director of information-processing techniques at the Defense Department's advanced research projects agency until 1973, when he began the organization of Telenet.