Bulgarian state-owned railway company BDZ Passengers said its 18.7 million levs ($11.0 million/9.6 million euro) tender for providing insurance of its rolling stock and properties has been suspended due to a complaint from Sofia-based DZI - General Insurance company.The complaint concerns all three lots of the tender, BDZ Passengers said in a notice last week.According to information published by the Commission for Protection of Competition, the anti-trust regulator launched proceedings on Friday in relation to a complaint against the tender filed by DZI - General Insurance.In its complaint, submitted to the competition authority on July 20, DZI - General Insurance contests the decision of BDZ Passengers to open the tender on June 28 and requests the temporary suspension of the procedure until the anti-trust regulator rules on the complaint.BDZ Passengers' tender envisages the signing of five-year insurance contracts.BDZ Passengers is a unit of state-owned railways company BDZ Holding.(1 euro = 1.95583 levs)