A new academy in Telford has been rated "inadequate" by Oftsed inspectors.
It is the first Ofsted inspection at Wrockwardine Wood since it became an arts academy in 2013. The secondary school was previously ranked "good".
Achievements in maths and English had declined while disadvantaged students were falling behind, the report found.
The Telford Co-operative Multi-Academy Trust (TCMAT) said it would not comment until Ofsted reports had been published on all four of its schools.
The four reports are expected to be published by the end of the week.
Arts subjects praised
Ofsted inspectors, who visited Wrockwardine Wood in New Road in February, said the proportion of students making expected progress in maths and English was "too low and has declined".
Inspectors also noted "low-level disruption" was hindering learning in some lessons and that school governors had an "overgenerous view" of how well the academy was doing.
However, the report found that students achieved well in some subject areas, particularly arts-related ones such as music and dance.
It also found pupils felt "well cared for" and the relationship between staff and students was positive.
The school is set to merge with Sutherland Co-operative Academy, which is also run by TCMAT, at the end of July to form a new academy.