Article 155. Types of procedures.

1. For the award of public contracts, contracting authorities and granting bodies use open, restricted or negotiated award procedures preceded by a call for tenders, competitive dialogues or innovation partnerships, in accordance with the provisions of this Part. 2. Only in the cases provided for in Article 158, contracting authorities and granting bodies may use the negotiated procedure without publication of the notice. 3. The tender is announced with one of the following methods: a) a periodic indicative notice in accordance of Article 161, if the contract is awarded by restricted or negotiated procedure; (b) a notice on the existence of a qualification system in accordance with Article 162, if the contract is awarded by restricted or negotiated procedure or through a dialogue competitive or an innovation partnership; c) through a tender notice pursuant to article 163. 4. In the case referred to in paragraph 3, letter a), the economic operators who have expressed interest following the publication of the indicative periodic notice are subsequently invited to confirm your interest in writing, pursuant to Article 165. EFFECTIVE FROM: 1 July 2023