The Unitary Socialist Party–Socialist Agreement (Italian: Partito Socialista Unitario–Intesa Socialista, PSU–IS) was a political party in San Marino.
The party was formed in 1975 when the Sammarinese Independent Democratic Socialist Party split into two; one faction forming the Unitary Socialist Party and the other forming Socialist Democracy.[1] The PSU received 11% of the vote in the 1978 elections, winning seven seats. It subsequently joined the governing coalition alongside the Sammarinese Socialist Party (PSS) and the Sammarinese Communist Party (PCS).[2]
PSU sent three delegates to the congress of the Socialist International in 1980; Pier Paolo Gasperoni, Emilio della Balda and Dominique Morolli.[3] In the 1983 elections it won eight seats.
In the mid-1980s the party was renamed Unitary Socialist Party–Socialist Agreement. It won eight seats again in the 1988 elections, emerging as the third-largest party. It subsequently merged into the PSS.[1]