Cooke Media Group Inc., a company formed to acquire and operate Jack Kent Cooke's media interests, has formally registered with the Securities and Exchange Commission a heavily discounted $430 million note and a $300 million debenture offering.

The media firm, a wholly owned subsidiary of the Middleburg, Va., millionaire's Jack Kent Cooke Inc. sold the securities privately through Drexel Burnham Lambert Inc. last April.

The print and broadcast media holding company did not name the securities' buyers in its registration statement. But in order to allow resale of the notes and debentures, Cooke Media is required to register the offerings with the SEC.

According to the filing, Cooke Media financed its $755 million acquisition of McCaw Cablevision Inc. and $160 million of its $176 million purchase of the Los Angeles Daily News in December 1985 with about $250.9 million it received from the sale of the notes and the $300 million debentures.

The two acquisitions also required $274 million from a $300 million Bank of America revolving credit line, and $125 million from Jack Kent Cooke Inc. equity.

Cooke's media firm is highly leveraged as a result of the acquisition. As of March 29, the company reported, it had an accumulated deficit of $24.96 million.

Cooke Media's fixed charges exceeded earnings by $100.39 million for 1986, and by $21.68 million for the first quarter of this year.

Cooke's acquisition of Kirkland, Wash.-based McCaw in April added 434,444 basic subscribers in 11 states to Cooke Media's Cablevision Inc. operation.