Short answer. No. Silence in the partnership agreement does not permit the industrial partner to run a separate business. The Civil Code requires express permission. Without it, the industrial partner is prohibited from engaging in business for himself, and the capitalist partners can either expel him or claim whatever he earned.
What the law says
An industrial partner cannot engage in business for himself, unless the partnership expressly permits him to do so
Civil Code, Article 1789 — Industrial Partner's Exclusivity. Read the full provision →
Silence is not permission — express authorization is required
Article 1789 of the Civil Code sets a clear default: an industrial partner cannot run his own business unless the partnership expressly permits him to. The word "expressly" matters. Implied permission is not enough. Silence in the partnership agreement is not enough. If the agreement does not affirmatively grant the industrial partner the right to engage in outside business, the prohibition applies automatically. The burden is not on the capitalist partners to object; the burden is on the industrial partner to show that the agreement explicitly allows it.
Why the law imposes this restriction
An industrial partner contributes labor, skill, or industry instead of money or property. The capitalist partners are trusting that the industrial partner's time and effort will be directed toward the partnership's benefit. If the industrial partner is free to run a competing or even unrelated business on the side, the capitalist partners may not be getting what they bargained for. The restriction ensures that the partnership's human resource — the industrial partner — is genuinely working for the partnership, not splitting effort and attention between the firm and personal ventures.
What the capitalist partners can do if he violates the rule
If an industrial partner runs a business without express permission, the capitalist partners have two remedies to choose from. First, they may exclude him from the firm — effectively expelling him from the partnership. Second, they may choose to take the benefits he obtained from the unauthorized business, essentially claiming the profits of his outside venture for the partnership. In either case, the capitalist partners also have a right to damages. The choice between exclusion and benefit-seizure belongs to the capitalist partners, not the industrial partner.
If you are the industrial partner
If you are an industrial partner and you want to run a separate business — even one unrelated to the partnership's activities — you need the partnership's express written authorization before doing so. Operating first and asking later puts you at serious risk: the capitalist partners can retroactively claim everything you earned from the outside business and still expel you. If the partnership agreement is silent, approach the other partners now, and have the authorization put in writing as an amendment to the agreement or a separate resolution signed by all partners.