Since Austrians like Karl Weigl, Hans Gal, Ernst Toch. Egon Wellesz were already well-established composers before they emigrated to The USA or UK I am counting them as Austrians :)
HANS GAL: A CATALOGUE OF THE ORCHESTRAL MUSIC
1910-11:Three Songs for male chorus and small orchestra, op.11
1916: "The tree that wanted different leaves" for contralto, female chorus and small orchestra, op.2: 27 minutes
1916/37:Serbian Tunes for small orchestra, op. 3
1919: Fantasias for contralto, female chorus and small orchestra, op.5:20 minutes
1922: Requiem for Mignon for baritone, chorus, organ and orchestra, op. 26: 30 minutes
1923: Overture to a Puppet Play, op. 20: 8 minutes
1924: Divertimento for small orchestra, op.22a: 25 minutes
1926: Promenade Music for military band: 11 minutes + (Wergo cd)
1927: Symphony No.1 (Sinfonietta), op.30: 30 minutes + (Avie cd)
1929: Ballet Suite "Scaramuccio", op.36: 25 minutes
1930: Suite "The Magic Mirror" for orchestra, op. 38: 20 minutes
1932: Violin Concerto, op.39: 25 minutes + (Gramola and Avie cds)
1934: Concertino for Piano and String Orchestra, op. 43: 15 minutes
Improvisation, Variation and Finale on a Theme by Mozart for mandolin orchestra, op.60: 15 minutes
1936-37:Cantata "De Profundis" for soprano, contralto, tenor, baritone, chorus and orchestra, op.50: 75 minutes *
1937: Serenade for string orchestra (or mandolin orchestra), op. 46: 13 minutes + (CBC cd)
1939: Concertino for Violin and String Orchestra, op. 52: 19 minutes + (Avie cd)
1939-44:A Pickwickian Overture, op. 45: 10 minutes
1942-43:Symphony No.2 in F major, op.53: 47 minutes + (Avie cd)
1944-49:Cello Concerto, op. 67: 32 minutes * + (Avie cd)
1945: "Liliburlero: Improvisations on a martial melody" for orchestra, op. 48: 20 minutes
1948: Concertino for Organ and String Orchestra, op.55: 20 minutes + (Membran cd)
Piano Concerto, op. 57: 34 minutes
1949: Caledonian Suite-Scottish tunes for small orchestra, op.54: 15 minutes
1949-50:Suite for Viola or Alto Saxophone and small orchestra, op.102 a and b:20 minutes
1951: Lyrical Suite "Of a Summer Day" for female chorus with soprano and mezzo-soprano soloists and string orchestra, op. 77
1951-52:Symphony No.3 in A, op.62: 34 minutes + (Avie cd)
1954: "Biedermeier Dances" for large mandolin orchestra, op. 66: 8 minutes
1954-55:Suite "Meanders" for orchestra, op.69: 21 minutes
1955: Symphonic Cantata "Life Cycles" for soprano, contralto, tenor, baritone, chorus and orchestra, op.70: 90 minutes
1957: Music for String Orchestra, op. 73: 20 minutes *
1958-59: "Idyllikon" for small orchestra, op.79: 29 minutes
1961: Concertino for Treble Recorder or Flute and string orchestra, op. 82:20 minutes + (Dutton cd)
1965: Prelude to a Pageant for orchestra
"Into New Rooms" for chorus and small orchestra
Concertino for Cello and String Orchestra, op. 87: 25 minutes *
1966: Sinfonietta No.2 in E for mandolin orchestra, op.86: 19 minutes + (Antes cd)
1970: Triptych for orchestra, op.100: 27 minutes + (Avie cd)
1974: Symphony No.4 "Sinfonia Concertante" for Flute, Clarinet, Violin, Cello and Orchestra, op.105: 40 minutes + (Avie cd)