BANGKOK (Reuters) - Thailand's largest mobile operator Advanced Info Service Pcl (AIS) said on Friday it plans to invest 7 billion baht ($198.53 million) this year to expand its fixed broadband network to serve 6.5 million households by the end of 2016.

AIS, 23 percent owned by Singapore Telecommunications Ltd , aims to be one of the leading high-speed broadband internet providers over the next three to five years, Siraphop Paphatthananan, investor relations' official at AIS, said at a quarterly earnings briefing.

Thailand's broadband penetration is expected to rise to 50 percent of households by 2020 from 30 percent in 2015 when 20.6 million households connected to fixed high-speed internet, Siraphop said.

True Corp is the market leader in the high-speed broadband market and runs the country's third largest mobile network.

The fixed broadband business is part AIS's drive to become a full service telecoms provider, and the company will focus on digital content to help boost data usage to offset falling revenue from voice services, Siraphop said.

AIS won a license in May to operate a fourth-generation (4G) mobile phone network, in the last of a series of government spectrum auctions. It was the only bidder, and is paying about $2.12 billion for the spectrum.

(Reporting by Khettiya Jittapong and Manunphattr Dhanananphorn; Editing by Muralikumar Anantharaman)