HANOI, May 18 (Reuters) - Vietnam's Communist Party has named police minister To Lam as the state president, the government said on Saturday, and also nominated a new head of the parliament in a major leadership reshuffle.

Unprecedentedly for a one-party nation once known for its stable politics, two state presidents and a parliament speaker have stepped down in less than 18 months, all for unspecified "wrongdoing" amid a major anti-graft campaign which is unnerving foreign investors because of its chilling effect on bureaucracy.

After approval from parliament, which could come next week, General Lam, 66, will replace Vo Van Thuong, who stepped down in March after being accused of violating party rules, just over a year after his appointment.

Lam will retain his police minister job even after being elected as state president, according to Bui Van Cuong, the parliament's general secretary.

"The Politburo hasn't nominated a new Minister of Public Security, and therefore the National Assembly will not vote to dismiss this post during its upcoming session," Cuong told a press conference on Sunday.

Widely considered one of the most powerful figures in the country, Lam was chosen by the party's Central Committee earlier this week, but authorities and state media revealed the nomination only on Saturday.

The president holds a largely ceremonial role but is one of the country's top four political positions. The others are the party chief, the prime minister and the parliament speaker.

Many observers see his appointment as a possible step towards becoming party chief, the country's top job, when current terms for leadership posts end in 2026 - or even earlier, if the ageing general secretary Nguyen Phu Trong steps down before his third mandate expires.

The party also named Tran Thanh Man as the new chairman of the National Assembly, replacing Vuong Dinh Hue, who resigned last month over "violations and shortcomings". Man, 61, has served as deputy chairman of the parliament since 2021.

The nominations of Lam and Man have received "broad support" from the Central Committee, the government said in a statement.

The nominations came as the party named four new members of the Politburo on Thursday, the country's top decision-making body, after removing its fifth-ranking leader Truong Thi Mai from the group, the sixth to leave the Politburo since late 2022 in the unprecedented series of high-level resignations.

Photo from Bloomberg