Raymarine confirmed it has received two further takeover approaches, including one from a direct competitor, which it says was the highest of the approaches.
Last month, the company also announced it had been approached by a third party interested in buying the company.
Raymarine officials said in a statement it believes the proposal from its unnamed direct competitor "is highly likely to be subject to an in-depth review by the competition authorities and that anti-trust approval is unlikely to be secured."
Also, the company said, a protracted anti-trust approval process could be highly damaging to the company.
"The board therefore considers that the other two proposals have significantly greater likelihood of delivering value for shareholders and is continuing to investigate these proposals," Raymarine said in a statement. "However, there is no certainty that an offer will be made, nor as to the terms on which any offer might be made."