HZ Infrastruktura has selected Comsa for the modernisation, expansion and electrification of the 44 km Hrvatski Leskovac – Karlovac railway line. The contract includes the reconstruction of the existing line, double-track expansion, work on bridges and viaducts, the modernisation of stations and stops, as well as the renewal of electrical and signalling systems. This section is part of the Zagreb – Rijeka corridor and is considered an important link to the Port of Rijeka. HZ Infrastruktura valued the newly tendered project at around EUR 255 million net, while Comsa's bid was around EUR 278.8 million net or EUR 348.5 million gross. Previously, in July 2022, HZ Infrastruktura awarded a contract for construction and electrical work on the same section, worth around EUR 227.4 million, to a Strabag consortium. AZD Praha was awarded the contract for control-command and signalling (CCS) technology worth EUR 35 million at that time. However, according to regional reports, the earlier tendering process did not progress as planned because not all the necessary permits were in place. Following an amicable settlement with Strabag, HZ Infrastruktura re-tendered the project at the end of 2024. The client rejected further objections to the new award. According to Croatian media, construction was scheduled to begin in the summer of 2026. Upon completion, speeds of up to 160 km/h are planned.