Billionaire Tan Sri Vincent Tan, the 10th richest man in the country according to Forbes, has been slowly increasing his stake in Redtone International Bhd.

According to Bursa Malaysia filings, Tan purchased 3.5 million Redtone shares on June 3 from the open market.

The acquisition, which was believed to be done at a price between 71 sen and 77.5 sen per share, could cost as much as RM2.7 million.

Analysts said the purchase is a sign of the billionaire's confidence in the telecommunications company. They also believed that Redtone, which suffered a few consecutive years of losses in the past, may see better days ahead.

"I think the acquisition is driven by a few factors. First, is that the company is showing signs that the days of being in the red are over.

"Secondly, the company may emerge as the winner in the digital terrestrial TV broadcast (DTTB) bid. Also, I see synergies between Redtone's business and some of Tan's investments," said a head of research from a local brokerage when contacted.

The acquisition has also increased Tan's indirect stake to 13.86 per cent, from about 13.1 per cent previously. He now indirectly has 66 .2 million Redtone shares.

Prior to the June 3 acquisition, Tan, via Berjaya Philippines Inc, has bought 3 million and 10.1 million Redtone shares on May 23 and May 22, respectively. The acquisition in May 2013 was Tan's first purchase for over a year.

The company's 49 per cent-owned REDtone Network Sdn Bhd is currently one of the three shortlisted companies for the DTTB tender.

REDtone Networks - which is 51 per cent owned by Sultan of Johor, Sultan Ibrahim Ismail - is working with China's Huawei, Media Broadcast GmbH and PwC in its DTTB bid.

The DTTB bid is for the building, operating and managing of the sole digital terrestrial TV infrastructure in the country.

Redtone shares closed 6 per cent lower on Bursa Malaysia on Tuesday at 68 sen, with more than 11 million shares changed hands.

Year to date, Redtone shares have gained by more than 67 per cent.