NEW YORK — After a 3 1/2 month struggle, QVC Network may be close to declaring itself the winner of Paramount Communications.

Viacom Inc., QVC’s foe in the battle for the movie studio, has until 5:30 p.m. today to file an amended bid with the Securities and Exchange Commission.

As of press time Thursday, Viacom had not changed its bid.

QVC’s offer is valued at $9.6 billion and Viacom’s, at around $9.4 billion.

Once the winning bid is in, the tender offer must stay open for an additional 10 days. But the drama could play on.

“There are things that nobody thought of,” said a source close to the bidding. “What happens, if after the 10-day period, no one gets 51 percent of the stock?”

Paramount declined comment on that question, but an industry expert said if neither got 51 percent of the stock, both parties could extend their offers and, potentially, raise their bids.

For the last week, Viacom has been rumored to be negotiating with its equity partners, Blockbuster Entertainment Corp. and Nynex Corp., for additional investments.

“The only two parties who don’t think they’re in very expensive land seem to be Barry Diller, [QVC’s chairman] and Sumner Redstone [chairman of Viacom],” said James M. Meyer, director of research for Janney, Montgomery Scott in Philadelphia. “They have separated from a lot of Wall Street on just how much [their] vision is worth.”

Meyer said both Nynex and Blockbuster want a stronger voice in the new company. The sticking point in the negotiations has been the fact that they all have their own — sometimes competing — agendas.

On Thursday, Paramount’s stock closed at 78 1/2, up 1/4 on the New York Stock Exchange. Viacom’s stock closed on the NYSE at 47, down 7/8, and QVC’s stock closed at 39 1/2, down 1 on NASDAQ.