(Adds details and background) Jan 6 (Reuters) - Australian gas...

(Adds details and background)

Jan 6 (Reuters) - Australian gas producer Strike Energy (STX) said on Friday its takeover offer for Perth-based Warrego Energy (WGO) is at a premium to Hancock Energy's sweetened offer, as the tussle for the oil and gas explorer intensifies.

Strike's all-scrip bid of 37.5 Australian cents per share, based on its closing share price on Jan. 5, values Warrego at about A$459 million ($310.24 million). The offer also represents a 4.2% premium to Hancock's sweetened 36 Australian cents-per-share bid announced on Thursday, and values Warrego at A$440 million.

Warrego, which holds the West Erregulla Gas Fields in Western Australia, has been at the center of a number of buyout bids in the recent past, attracting offers from gas players such as Beach Energy (BPT) in the past.

Hancock Energy said in a bidder's statement on Thursday its offer extended to Warrego shareholders, who had earlier accepted its lower offer of 28 Australian cents apiece, but were conditional on the energy company achieving 40% shareholder acceptance.

Australian business magnate Gina Rinehart's Hancock Energy currently holds more than 25% of Warrego Energy, while Strike holds a 19.9% stake.

Warrego and Hancock did not immediately respond to a Reuetrs request for a comment.

($1 = 1.4795 Australian dollars)