The first round of bids were due this week for Hulu, the popular online TV service whose prospective sale has attracted interest from digital media players as well as cable operators. An initial bid has been submitted by the Chernin Group, a next-generation media company founded by longtime News Corp. executive Peter Chernin, which is partnering with Providence Equity, according to several people familiar with the matter. Guggenheim Digital Media, a group headed by former Yahoo Inc. interim Chief Executive Ross Levinsohn, also submitted a bid, say the people with knowledge of the situation who declined to be identified because of the confidential nature of the bidding process. Guggenheim is interested in expanding its media holdings, which include Prometheus Global Media, which owns a number of trade publications, including Adweek, Billboard and the Hollywood Reporter.