Univision first-round bids delayed.

The deadline for initial bids for U.S. Spanish-language broadcaster Univision Communications Inc. has been delayed to give the two main bidders time for adequate due diligence and to assure a competitive process, sources close to the matter said on Friday.

One source close to the deal said first round bids are now due June 20. That compares with a previous deadline of June 8.

Another source familiar with the matter said Mexican media powerhouse Televisa is moving more slowly than expected with its efforts to pursue the company as part of a private equity bidding group.

Televisa, which is working with a Bill Gates investment fund called Cascade Investment and four other private equity firms, is the lone corporate bidder so far in the auction, which has otherwise been dominated by private equity funds.

Televisa, which has also teamed up with Kohlberg Kravis Roberts & Co. [KKR.UL], Bain Capital, Blackstone Group [BG.UL], and Carlyle Group [CYL.UL], declined to comment.

The other bidding group includes Egyptian-born media investor Haim Saban as well as Madison Dearborn Partners, Providence Equity Partners, Texas Pacific Group [TPG.UL], and Thomas H. Lee Partners [THL.UL].

UBS, the investment bank advising Univision, wants to make sure that the two bidding groups have enough time to do due diligence in what is expected to be a complex and competitive transaction, the sources told.

Televisa already holds an 11.4 percent stake in Univision, which may hand an advantage to whatever group includes Televisa despite disagreements between Univision and Televisa on issues concerning television royalties and Internet rights.

Televisa said on Thursday it would not join Saban to buy Univision, which could be valued at more than $12 billion, even if its group's bid is rejected.

Univision put itself up for sale in February.

Its main attraction to buyers is its growth potential, as the Spanish-language advertising market in the United States has lagged the rapid growth of Hispanic audiences in the country.

Unlike other U.S. networks, Univision only has one major competitor in the market, NBC's Telemundo.