SYDNEY, March 18 (Reuters) - Nine Entertainment Co Ltd (NEC),...

SYDNEY, March 18 (Reuters) - Nine Entertainment Co Ltd (NEC), Australia's top-rating free-to-air television broadcaster, bought a 9.99 percent stake in Southern Cross Media Group Ltd (SXL) for A$88 million, Nine said on Friday.

Nine disclosed the deal in a one-sentence statement to the Australian Securities Exchange after investment bank Macquarie Group Ltd (MQG) put part of its quarter stake in the radio and television company up for sale late on Thursday.

The statement said Nine paid A$1.15 per Southern Cross share, a slight discount to its A$1.18 closing price on Thursday. In Australian takeover laws, parties are required to clear several regulatory hurdles to buy 10 percent or more of a company.

Although relatively small by dollar value, the deal heralds the start of a wave of M&A activity many expect to take place in the Australian media industry if the government succeeds in a plan to deregulate the country's media ownership laws.

Since the 1980s, Australian media companies are not allowed to own television, radio and print media assets in a single location, and a broadcaster may not have more than 75 percent of an audience.

But Prime Minister Malcolm Turnbull has said he plans to throw out those restrictions, citing media industry complaints that the rules have become redundant following the rise of online publishing.