"My father travelled to france to sell goods there" or My father travelled to france to negotiate the selling of goods there.

"My father travelled to France to negotiate the selling of goods there" means he went there to try and work out a deal that was mutually beneficial to the parties, discuss the terms of the contract, the delivery, the payment etc. "My father travelled to France to participate in the selling of goods there" means he went there to take part in the sale process. He could have participated in a certain aspect of the deal e.g. as the attorney, as the broker, or simply could have been a part of some or all of the negotiations. You therefore can use both terms depending on the role played by the father. Negotiate is more specific here with respect to the father's role ( as a negotiator), whereas participate is more general. I hope this assists you. Teacher Mark

It is negotiate