Chinese conglomerate HNA Group Co. agreed to buy a controlling stake in Tysan Holdings Ltd. for about $340 million to expand in construction and property development, prompting shares of the target company to jump to the highest level in 25 years. HNA will pay HK$2.62 billion ($340 million), or HK$4.53 a share, to an arm of Blackstone Group LP for a 66 percent stake in Tysan, the construction company said in a filing to the Hong Kong Stock Exchange. The price is about 11 percent more than Tysan’s closing level on March 31. Trading was suspended April 1. The acquisition would help HNA, the owner of Hainan Airlines Co. as well as hotel, infrastructure, logistics and aviation-maintenance businesses, extend its foothold outside mainland China after agreeing to buy a stake in Brazilian airline Azul Linhas Aereas Brasileiras SA and acquiring airport luggage handler Swissport International Ltd. for about $2.7 billion. China has urged its companies to expand overseas to improve competitiveness, helping result in $97 billion in deals in the first quarter. Tysan gained 5.1 percent to close at HK$4.30 in Hong Kong, the highest since at least April 1991, after trading resumed Tuesday. The shares gained 60 percent in the 12 months before trading was suspended April 1, compared with a 17 percent decline for the city’s benchmark Hang Seng Index. “The market may be expecting HNA needs to raise the bid to something more expensive,” Mark Jolley, equity strategist at CCB International Securities, said by phone.  Under the terms, Blackstone would receive 58 percent more than the HK$2.86 a share it paid to buy the Tysan stake in a deal completed in 2014, according to data compiled by Bloomberg. Tides Holdings II, the Blackstone arm, will still own 9 percent of Tysan after the sale of the 577.3 million shares, equivalent to 66 percent of the company. HNA’s purchase will trigger a mandatory unconditional offer to buy the remaining shares in Tysan, according to the statement issued Monday after the market’s close. HNA also signed a letter of intent to buy 40 percent of Tysan Foundation (Hong Kong) Ltd. from Fortunate Pool Ltd., a wholly owned company of Tysan’s vice chairman and managing director Victor Fung, for HK$836.6 million. The remaining 60 percent is owned by Tysan Group. The conglomerate was also said to be one of the bidders for London City Airport this year, before losing out to a consortium led by Ontario Teachers’ Pension Plan Board. China has undertaken a so-called “One Belt, One Road” initiative, a $40 billion strategy that aims to strengthen economic and transport ties across Eurasia, while raising the world’s second-biggest economy’s profile as a global power. The project is part of Chinese President Xi Jinping’s efforts to revive the ancient trade route and finance infrastructure construction there. Tysan Group’s main business is in foundation piling, accounting for about three quarters of revenue in the fiscal year ended March last year, according to data compiled by Bloomberg. The company was involved in construction projects such as laboratories at the Chinese University of Hong Kong and Cathay Pacific Airways Ltd.’s air cargo terminals at the city’s airport, according to its website. It also took part in works in the expansion of Sands casino in Macau and a tower development at the Venetian. Its operations include property development, a business that accounted for about 20 percent of revenue, according to data compiled by Bloomberg. It has completed at least two projects in Shanghai, with two more under construction, its website shows. The Tysan transaction is subject to a definitive sale and purchase agreement and terms and conditions, and there is no certainty the deal will proceed, Tysan said. Tides Holdings II had said March 9 that it was in talks with an independent third-party regarding a sale of Tysan shares.