Context : Interacting galaxies surrounded by H i tidal debris are ideal sites for the study of young clusters and tidal galaxy formation .
The process that triggers star formation in the low-density environments outside galaxies is still an open question .
New clusters and galaxies of tidal origin are expected to have high metallicities for their luminosities .
Spectroscopy of such objects is , however , at the limit of what can be done with existing 8-10m class telescopes , which has prevented statistical studies of these objects .

Aims : NGC 2865 is an UV-bright merging elliptical galaxy with shells and extended H i tails .
The regions observed in this work were previously detected using multi-slit imaging spectroscopy .

Methods : We obtain new multi-slit spectroscopy of six young star-forming regions around NGC 2865 , to determine their redshifts and metallicities .

Results : The six emission-line regions are located 16-40 kpc from NGC 2865 and they have similar redshifts .
They have ages of \sim 10 Myears and an average metallicity of \sim 12+log ( O/H ) \sim 8.6 , suggesting a tidal origin for the regions .
It is noted that they coincide with an extended H i tail , which has projected density of N _ { HI } < 10 ^ { 19 } cm ^ { -2 } , and displays a low surface brightness counterpart .
These regions may represent the youngest of the three populations of star clusters already identified in NGC 2865 .

Conclusions : The high , nearly-solar , oxygen abundances found for the six regions in the vicinity of NGC 2865 suggest that they were formed by pre-enriched material from the parent galaxy , from gas removed during the last major merger .
Given the mass and the location of the H ii regions , we can speculate that these young star-forming regions are potential precursors of globular clusters that will be part of the halo of NGC 2865 in the future .
Our result supports the use of the multi-slit imaging spectroscopy as a useful tool for finding nearly-formed stellar systems around galaxies .