Article 157. Transactions Concluded under Condition see also Termination
1. A transaction shall be considered concluded under a condition suspensive if the parties have made the arising of rights and duties dependent upon a circumstance relative to which it is unknown whether this will ensue or not.
2. A transaction shall be considered concluded under a condition subsequent if the parties have made the termination of rights and duties dependent upon a circumstance relative to which it is unknown whether this will ensue or not.
3. If the ensuing of a condition is obstructed in bad faith by a party for which the ensuing of the condition is disadvantageous, the condition shall be deemed to have ensued. If the ensuing of a condition is facilitated in bad faith by a party for which the ensuing of the condition is advantageous, the condition shall be deemed not to have ensued
Article 425. Validity of Contract.
1. A contract shall enter into force and become binding for the parties from the moment of its conclusion.
2. The parties shall have the right to establish that the conditions of a contract concluded by them shall apply to their relations which arose before the conclusion of the contract.
3. It may be provided for by a law or contract that the expiry of the term of validity of a contract shall entail the termination of the obligations of the parties under the contract. A contract which lacks such a condition shall be deemed to be in force until the moment established therein for the ending of performance of the obligation by the parties.
4. The expiry of the term of validity of a contract shall not relieve the parties from responsibility for the violation thereof.
Article 429. Preliminary Contract.
1. Under a preliminary contract, the parties shall undertake to conclude in future a contract concerning the transfer of property, performance of jobs, or providing of services (prime contract) on the conditions provided for by the preliminary contract.
2. A preliminary contract shall be concluded in the form established for a prime contract, and if the form of the prime contract has not been established, then in writing. The failure to comply with the rules concerning the form of the preliminary contract shall entail its nullity.
3. A preliminary contract may contain conditions enabling to establish the subject, as well as other material conditions of the prime contract.
4. A preliminary contract shall specify the period in which the parties undertake to conclude the prime contract.
If such period has not been determined in the preliminary contract, the prime contract shall be subject to conclusion within a year from the moment of concluding the preliminary contract.
5. In instances when a party which has concluded a preliminary contract evades from concluding the prime contract, the provisions established by Article 445(4) of this Code shall apply.
6. The obligations provided for by a preliminary contract shall terminate if before the expiry of the period during which the parties must conclude the prime contract it has not been concluded or one of the parties has not sent to the other party an offer to conclude this contract.
Article 434. The Form of the Contract see also validity
1. The contract may be concluded in any form, stipulated for making the deals, unless the law stipulates a definite form for the given kind of contracts. If the parties have agreed to conclude the contract in a definite form, it shall be regarded as concluded after the agreed form has been rendered to it, even if the law does not require such form for the given kind of contracts.
2. The contract in written form shall be concluded by compiling one document, signed by the parties, and also by way of exchanging the documents by mail, telegraph, teletype, telephone, by the electronic or any other type of the means of communication, which makes it possible to establish for certain that the document comes from the party by the contract.
3. The written form of the contract shall be regarded as observed, if the written offer to conclude the contract has been accepted in conformity with the order, stipulated by Item 3, Article 438 of the present Code.