Section 190 in The Indian Contract Act, 1872
Title: When agent cannot delegate.
An agent cannot lawfully employ another to perform acts which he has expressly or impliedly undertaken to perform personally, unless by the ordinary custom of trade a sub-agent may, or, from the nature of the agency, a sub-agent must, be employed.
Title: "Sub-agent" defined
A "sub-agent" is a person employed by, and acting under the control of, the original agent in the business of the agency.
Title: Representation of principal by sub-agent properly appointed.
Where a sub-agent is properly appointed, the principal is, so far as regards third persons, represented by the sub-agent, and is bound by and responsible for his acts, as if he were an agent originally appointed by the principal.
Agent's responsibility for sub-agent.—The agent is responsible to the principal for the acts of the sub-agent.
Sub-agent's responsibility.—The sub-agent is responsible for his acts to the agent, but not to the principal, except in cases of fraud or wilful wrong.
Title: Agent's responsibility for sub-agent appointed without authority.
Where an agent, without having authority to do so, has appointed a person to act as a sub-agent, the agent stands towards such person in the relation of a principal to an agent, and is responsible for his acts both to the principal and to third persons; the principal is not represented, by or responsible for the acts of the person so employed, nor is that person responsible to the principal.
Title: Relation between principal and person duly appointed by agent to act in business of agency.
Where an agent, holding an express or implied authority to name another person to act for the principal in the business of the agency, has named another person accordingly, such person is not a sub-agent, but an agent of the principal for such part of the business of the agency as is entrusted to him.
(a) A directs B, his solicitor, to sell his estate by auction, and to employ an auctioneer for the purpose. B names C, an auctioneer, to conduct the sale. C is not a sub-agent, but is A's agent for the conduct of the sale.
(b) A authorizes B, a merchant in Calcutta, to recover the moneys due to A from C & Co. B instructs D, a solicitor, to take legal proceedings against C & Co. for the recovery of the money. D is not a sub-agent, but is solicitor for A.