MANILA (BLOOMBERG) - Shares of PhilWeb Corp fell the most on record on Thursday (Aug 4) after tough-talking Philippine President Rodrigo Duterte named the online gambling company's chairman as among businessmen with alleged political connections that he seeks to target.

Mr Duterte plans to "destroy the oligarchs that are embedded in government," he said in a speech late on Wednesday, and named PhilWeb chairman Roberto Ongpin as an example.

"These are the guys who just sit in their jets and in their mansions everywhere, and their money trickle like a taxi meter," according to a video and transcript of his speech. The president did not specify any actions he planned to take on Ongpin.

PhilWeb shares fell as much as 50 per cent to 7.12 pesos (S$0.20), the biggest intraday drop since 1991 and the lowest level since December 2014, while the Philippine Stock Exchange Index rose as much as 1 per cent. The stock has been plunging since the start of July, after Mr Duterte ordered a stop to online gambling at his first cabinet meeting.

The president's speech was the main trigger for PhilWeb's dive on Wednesday, said Astro del Castillo, managing director at First Grade Finance Inc. in Manila. "Duterte is known to walk the talk and always hits the bull's-eye. Ongpin has a problem," he said.

Mr Ongpin, who had served as trade minister of late Philippine dictator Ferdinand Marcos and was a former deputy chairman of Hong Kong's South China Morning Post newspaper until last year, didn't reply to a call and text message to his mobile phone. PhilWeb's office didn't return three calls seeking comment.

PhilWeb president Dennis Valdes said when reached by telephone that he was in a meeting and couldn't speak.