Best Buy Co Inc agreed to extend the deadline to February 28 for founder Richard Schulze to make a bid for the company, continuing the uncertainty for shareholders over whether he can put a bid together.

Best Buy shares fell 13.5 percent to $12.22 on the New York Stock Exchange.

The company said on Friday the extension would allow Schulze to include the consumer electronics retailer's full-year results as part of his due diligence review.

The new deadline will also give him more time to line up partners and financing for a bid. A source told Reuters on Thursday that Schulze didn't have financing lined up in time for a December bid.

Schulze, who founded Best Buy in 1966, has said he would fund any deal through a combination of private equity and debt financing, as well as the reinvestment of some of his own equity in the company. He is Best Buy's biggest shareholder, with 20 percent ownership.

"Obviously with the extension, there is still some hesitation on the part of his private equity suitors about how much financing they would want to put up for this deal," Morningstar analyst R J Hottovy said.

Under the extension, Schulze will be able to submit an offer any time during February, and the company will have 30 days to review and make a decision on the bid.

(Writing by Brad Dorfman. Reporting by Dhanya Skariahcan and Olivia Oran in New York. Nivedita Bhattacharje in chicago and Siddharth Cavale in Bangalore; Editing by Jeffrey Benkoe)