The Kaunas Regional Court on Monday dismissed lawsuits by two other bidders, Versina and LitCon, in which the Vilnius-based engineering network companies contested the results of the bidding.
It also lifted interim protection measures applied to the contract in July, thus giving the go-ahead for continuing the reconstruction work.
The ruling can be appealed to the Lithuanian Court of Appeals within 14 days.
The Kaunas local authority signed the 46-million-euro contract with Kayi Insaat Sanayi ve Ticaret in mid-June, with plans to launch the reconstruction work in July and complete it within 20 months.
A total of eight suppliers participated in the public procurement process.