BANGKOK (Reuters) - Shares of companies linked to a billionaire politician who campaigned in Thailand’s election on a pledge to legalize marijuana leapt on Monday after partial results suggested his party could be a key part of a coalition government.

FILE PHOTO - Anutin Charnvirakul, the leader of the Bhumjaithai party gestures during an interview with Reuters in Bangkok, Thailand, November 22, 2017. Picture taken November 22, 2017. REUTERS/Panu Wongcha-um

Results from Sunday’s election showed that a pro-military party and an opposition party linked to the army’s nemesis, self-exiled former populist Thaksin Shinawatra, had won the largest share of parliament seats announced so far.

However, both the pro-army Palang Pracharat and the opposition Pheu Thai could seek support from Anutin Charnvirakul’s Bhumjaithai Party (Proud to Be Thai) to cobble together a majority of parliamentary seats needed to form a coalition government.

The Bhumjaithai Party won 39 of 350 lower house seats already decided. The winners of a further 150 seats, which were contested according to a system similar to proportional representation, may not be known before May 9.

Anutin, an amateur pilot, could be a compromise candidate for prime minister if neither of the two leading parties can form a government, and members of his party could receive influential ministry portfolios.

Sino-Thai Engineering and Construction Pcl shares closed up 3 percent and steelmaker STP&I Pcl rose 2.5 percent.

They bucked the Thai index, which closed down 1.2 percent on concerns that the election would be inconclusive and a broader regional decline.

Anutin holds a 10 percent stake in STP&I and is the former president of Sino-Thai Engineering and Construction.

“This is all knee-jerk reaction,” said Maria Lapiz, head of institutional research at Maybank Kim Eng Securities Thailand, adding that Sino-Thai’s balance sheets were already strong and would not be affected by the outcome of the election.

Anutin, which also backs a four-day work week and legalizing ride-hailing, was part of a previous Thaksin-led government but is also seen as close to the junta that took over after a 2014 military coup.

In 2018, junta Prime Minister Prayuth Chan-ocha visited Buriram province, Bhumjaithai’s stronghold, where thousands of supporters filled a stadium to welcome him. In October, ride-hailing startup Grab launched a program in Buriram to support the local economy.

Shares in Thaksin-linked companies fell on Monday amid concerns that Pheu Thai had fared worse than expected in the election. Real estate developer SC Asset Pcl closed down more than 5 percent and Praram 9 Hospital Pcl lost 2.7 percent.

Thaksin’s daughters hold a majority stake in SC Asset, while his ex-wife, Potjaman Damapong, holds 37 percent of Praram 9 Hospital.

However, analysts say the luxury condo and hospital sectors are not likely to be affected by the political changes ahead, while an increase in the minimum wage, promised by both the pro-military and opposition parties, could lift spending and help consumer goods companies.