HANOI, March 18 (Reuters) - A large U.S. business delegation, including Meta, Boeing and wind energy firm GE Vernova, is visiting Vietnam this week in a sign of continued corporate interest in the Southeast Asian nation after Washington upgraded ties last year.

About 50 companies will participate, according to organiser US-ASEAN Business Council, which last year brought a business delegation of similar size to Vietnam. Conglomerate Koch Industries, safety standards firm UL Solutions, insurance group Chubb, gaming company Roblox , weather forecasts provider ATMO and energy firm AES are also taking part.

Many of these companies are already active in Vietnam.

Meta's Facebook has over 60 million users in the country, making it one of its largest markets globally.

Boeing signed a preliminary deal with national carrier Vietnam Airlines last year for the sale of 50 of its 737 planes.

U.S. President Joe Biden upgraded relations with Vietnam last year and pushed for increased cooperation in the semiconductor industry. The organisers said, however, that no semiconductor firms are scheduled to join this week's business delegation.

The business mission will hold meetings with local authorities from Tuesday to Thursday. On Monday, a smaller delegation of security firms plans to discuss possible business opportunities with representatives from Vietnam's ministries of defence and police, according to the organisers.

(Reporting by Francesco Guarascio @fraguarascio; Editing by Edwina Gibbs)