TORONTO (Reuters) - Canada's auction of wireless spectrum ended on Monday, and new players appear poised to enter the market and challenge the country's Big Three carriers in a fight for mobile phone subscribers.

A government official told Reuters there had been two consecutive rounds in the auction with no new bids on Monday, prompting auction managers to call an end to the months-long process.

The auction of airwaves over which wireless services are delivered raised C$4.25 billion ($4.25 billion) in 331 rounds of bidding. The proceeds were more than twice the amount analysts had expected.

"Thank you for participating in the Advanced Wireless Services auction. The auction is now closed," the government stated simply to bidders in an online message.

According to the auction website, Rogers Communications Inc, which owns Canada's largest wireless firm, was the top bidder with offers totaling C$999.4 million.

Telus Corp, Canada's No. 2 phone company, had C$879.9 million in standing high bids. Telecom giant BCE Inc had bids totaling C$740.9 million.

The three companies currently dominate Canada's wireless landscape, though analysts have cautioned that their aggressive spectrum spending could leave them vulnerable to competitive threats posed by newcomers.

The government had set aside a chunk of spectrum exclusively for bidding on by new entrants -- a move the Big Three providers criticized as equal to an unfair subsidy.

As the auction concluded, Quebecor Inc, which had bid a total of C$554.5 million, and Globalive Communications, with bids totaling C$442.1 million, appeared to pose the most serious threat to the existing carriers.

Analysts have suggested that Quebecor, a printing and media firm with an established presence in its home province of Quebec, could partner with Globalive to create a national service provider.

A third participant that could shake up the market is Data & Audio-Visual Enterprises Wireless, chaired by entrepreneur John Bitove. It has a total of C$243.2 million in high bids. One of Bitove's partners in DAVE Wireless is the investment arm of Vulcan Inc., an organization founded by Paul Allen, a co-founder of software giant Microsoft Corp.

A fourth major bidder among the newcomers is Shaw Communications Inc, a Western Canadian cable and communications group. It had a total of C$189.5 million in standing high bids as the auction ended.

However, Shaw's chief executive has said that just because Shaw participated in the auction does not mean it will build out a network.

($1=$1 Canadian)

(Reporting by Wojtek Dabrowski and Louise Egan; editing by Rob Wilson)

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