Best Buy Co said on Wednesday it will offer products online from other sellers through a new third-party Marketplace as the electronics retailer tries to better compete with Internet rivals Amazon.com and eBay Inc.

Best Buy Marketplace will add roughly one-third more products online in time for the holiday shopping rush.

Buy.com, Mambate, SF Planet, ANT Online, BeachAudio.com and Wayfair are the third-party sellers that signed up for the launch.

Best Buy shares rose 3.8 percent to $24.18 in afternoon trading. The stock has lost almost one-third of its value so far this year.

Best Buy has suffered in recent quarters partly because customers visit the company's physical stores to see products and then go to another retailer online to buy. The Marketplace initiative may help Best Buy keep some of those lost sales.

Amazon.com, the world's largest Internet retailer, has a large third-party business that attracts many shoppers because they know they will likely find the product they are looking for on the website.

EBay runs a dedicated online market for other sellers that pulled in more than $5 billion in revenue last year.

Our multichannel strategy is all about taking advantage of the interplay between digital and physical -- being able to be present what the customer is searching for, whether on a cell phone, web browser or in store talking to associates, John Thompson, senior vice president of Best Buy and general manager of online operations, said in an interview.

Having access in the store to this expanded online assortment is part of that overall strategy, he added.

Third-party sellers on Best Buy's Marketplace will handle product shipping and returns. Customers will use the same single shopping cart and checkout process, Best Buy said.