UPDATE 1-Genting HK seeking shares in Australia's Echo-fund manager

* Genting Group subsidiary eyeing Echo's Sydney casino

* Definite interest, but not at price offered-fund manager

* Echo shares rally 3.4 percent on news buyer interested

(Adds details)

MELBOURNE, Oct 5 (Reuters) - Genting Hong Kong Ltd has approached shareholders of Echo Entertainment Group Ltd

seeking to boost its stake in the owner of Sydney's only casino, a fund manager who holds Echo shares said.

Genting Hong Kong has applied to Australian regulators to raise its stake in Echo to 25 percent, potentially pitting it in a battle for the company against Australian billionaire James Packer, who owns a 10 percent stake.

Two of Genting Group's subsidiaries - Genting Hong Kong (GHK) and Genting Singapore PLC - each bought almost 5 percent of Echo in June. Packer's Crown Ltd has already sought regulatory approval to boost its holding to 25 percent.

However, in a surprise move, Genting Singapore sold its stake last month in a $165 million deal, saying it wanted to "rationalise its investments portfolio."

The fund manager Reuters spoke to said he was approached by a broker on Thursday night to sell shares in Echo, and that he believed Genting Hong Kong was the buyer. He declined to be identified because the matter is confidential.

The fund manager said his firm was not interested in selling its Echo shares at the price offered by the broker of A$3.90.

Newspapers on Friday reported that a buyer believed to be Genting Hong Kong was seeking 40 million Echo shares, or 5 percent of the Australian casino operator.

A spokeswoman for Genting in Australia would not comment. Officials with Genting Hong Kong also declined to comment.

Echo shares rallied 3.4 percent on Friday to A$3.98, on turnover of 15.6 million shares.

A second source with direct knowledge of the situation said the broker seeking to buy Echo shares was RBS Morgans.

A spokesman for RBS Morgans declined to comment.

Last month, Genting Hong Kong said it remained committed to an application for regulatory approval to acquire up to 25 percent of the casino group.

On Friday, the regulator, the New South Wales Independent Liquor and Gaming Authority, said on its website it was calling for public submissions on Genting Hong Kong's application.

(Reporting by Victoria Thieberger; Additional reporting by Farah Master in HONG KONG; Editing by Matt Driskill and Ryan Woo)

((victoria.thieberger@thomsonreuters.com)(+61 3 9286 1421)(Reuters Messaging: victoria.thieberger.reuters.com@reuters.net))