A national "electronic university" offering college courses and direct communication with professors is offering 170 courses by home computer, a group of computer entrepreneurs announced yesterday.

The profit-making venture, called TeleLearning Systems, will sell equipment to connect home computers to professors via phone lines. The company also will recruit teachers--several thousand within the next two years--ranging from retired people to full professors at major colleges.

Secretary of Education T.H. Bell, who attended the announcement ceremonies, praised the new business and said the administration was "excited about the concept . . . .

"The thrilling thing about . . . the electronic university is its flexibility and its adaptability as far as its ability to reach all learners on all levels, and then to teach them where they are, and then to individualize the instruction for each and every student . . . ."

The idea is a cross between the correspondence course and the computer.

Americans now own about 11 million home computers and the number is expected to increase to more than 30 million within the next 18 months. More than 70 universities now offer about 12,000 different correspondence courses.

"The trouble is that when you are working on a course and you are interested, you want to communicate with the teacher, you want to get results of questions and tests back right now, not three weeks from now in the mail," said company Chairman Ronald F. Gordon, the former chief executive officer of Atari Inc.

The new system offers an "electronic mailbox" that allows teacher and student to send each other messages and test results daily.

The company now offers 170 courses from 200 teachers and backup instructors, with subjects ranging from human sexuality and "crap shooting for the innocent" to a lecture on James Joyce and lessons in contemporary American poetry. The company expects to offer about 500 courses from 800 teachers beginning early next year.

The courses will carry no formal credit, but the company has recruited 15 colleges and universities to try out the network.

Colleges may allow credit for the courses, Gordon said, and the company also will offer courses that will prepare students to take the degree-equivalency tests of many states and university systems, such as the New York Regents college equivalency exams.

Gordon said he believes that current negotiations will lead by next year to a number of colleges granting credit for courses offered by the company or the colleges themselves.

The system is to work this way: the owner of any of a wide variety of home computers, from the $200 to the $10,000 models, will buy from TeleLearning a "knowledge package" consisting chiefly of a course catalog and a sophisticated computer program linking the computer with the company's network of teachers.

The "knowledge package" will vary in price from just over $100 to about $230. The company expects to make its profit through sales of this package.

After the initial purchase of the package, a computer owner may sign up for any number of courses. The cost will vary according to how much the teacher charges per lesson-hour, ranging from $35 to $150 for courses from well-known professors or experts.

The course fee covers telephone charges and network transmission charges as well the "electronic lectures." The student will receive the text of lectures, and graphics to accompany them, transmitted from the teacher.

In addition to receiving prepared course material, the student will be able to stop in mid-lesson during certain hours each week and type out questions to the teacher, who will receive the question within seconds and be able to answer it immediately. This will allow direct communication between teacher and student.

Gordon predicted that within two years the "electronic university" would have a million students and become the world's largest private educational institution.

He said the company would not seek accreditation directly, but would work through established universities, businesses and government agencies, allowing them to write their own courses and use their own teachers over the network.