BUDAPEST—Hungary has offered to buy Budapest Airport from its foreign shareholders, part of an effort to take it back into state hands and protect what the government says are national interests. Prime Minister Viktor Orban’s government earlier this year expressed its interest in buying a majority stake in Hungary’s main international airport saying its past privatization had been against the country’s “strategic interests.” Orban, a nationalist often at loggerheads with the European Commission on a range of issues, has said he wants to see the airport in domestic hands, but until now its owners have expressed no interest in selling it. Since Orban took power in 2010, his government has boosted Hungarian ownership in strategic sectors such as energy, banking, and the media. The biggest shareholder in Budapest Airport with 55.44 percent is AviAlliance GmbH, formerly Hochtief AirPort GmbH, owned by Canada’s Public Sector Pension Investment Board (PSP Investments). AviAlliance …