NEW YORK (AP) _ Home Shopping Network Inc., which sells consumer goods via televised shopping programs, and Comb Co., a partner in a rival shopping network, said today that their merger talks have reached an impasse.

The companies said in a joint statement that ''while discussions are continuing with a view toward resolving the outstanding issues, no assurance can be given that the open issues will be resolved.''

A spokeswoman for Home Shopping, Judy Ludin, said she could provide no further details about what issues remain unresolved. She said Home Shopping Chairman Roy M. Speer and its president, Lowell Paxson, were unavailable for comment.

Theodore Diekel, chairman of Comb, was said by his office to be unavailable for immediate comment.

The prices of common stock in both companies fell in early trading.

Home Shopping stock was off $1.37 1/2 a share to $37.87 1/2 on the American Stock Exchange, while Comb stock was down $4.25 a share at $25.75 in over-the-counter trading.

The companies had announced Jan. 20 that they had reached an agreement in principle under which Home Shopping would pay $36 worth of its stock for each of Comb's 18 million common shares. That indicated the deal would be worth about $650 million.

Home Shopping, based in Clearwater, Fla., is the biggest entrant in the rapidly growing home shopping business.

It operates two shopping show networks through which its hosts demonstrate items ranging from jewelry to home computers and encourage viewers to phone in orders. It says its programs can be seen by about 40 million households.

Comb, based in Plymouth, Minn., is a mail-order marketer that also is a partner with cable television operators in a home shopping network called the Cable Value Network.

Analysts say Cable Value Network is the second biggest home shopping operation and estimate it can be seen by about 10 million households.