ATHENS, Nov 12 (Reuters) - Ten activists trying to take aid from Libya to Gaza jumped on board a ship about to set sail to Greece, the vessel's managers said on Friday, denying reports the aid workers were held against their will.

The Greek managing company said the captain pulled away from the port with the activists on board because he was afraid more would board and divert the ship to Gaza, which is under an Israeli naval blockade.

The Road to Hope charity and the Libyan coast guard said on Thursday the activists were being held by the captain of the ship, the Maltese-flagged Strophades IV, after a row over money, along with Libyan police officers.

The company, Ionian Bridge Shipmanagement, said ten of a group of around 150 activists jumped on the boat at the Libyan port of Derna and the captain was forced to set off to prevent all of them boarding and taking over the ship.

Strophades IV anchored off Greece's Piraeus port on Friday morning. Coast guard officials said the 16-member crew -- 10 Ukrainians and 6 Egyptians -- as well as the 17 other people on board, were all well.

They are not on this ship against their will, a spokeswoman for Ionian Bridge Shipmanagement, Maria Georgoulia, told Reuters by telephone, adding that there had been no deal with the activists to use the ship.

There was never an agreement. They didn't have documents showing they could travel with this ship. It would be illegal.

The company said in a statement it had held negotiations with an Egyptian agency for three days over the transport of the activists to Egypt, but no agreement had been reached.

We saw the activists' convoy arriving at the Derna port and we had no idea what was going on, the statement said.

We never intended to transfer the activists, because we realised they wanted to lead the ship not to El Arish but Gaza, to break the embargo and pitch us against the Israeli navy. We wanted to leave, fearing for our lives.

Greek coast guard officials declined to disclose whether the activists would be allowed to disembark soon. British embassy officials said they would provide consular assistance to them, if needed.

Gergoulia said the vessel had unloaded and was about to get permission to leave Derna for Piraeus when the activists went to ask the captain to take them to Egypt, though their final destination was probably Gaza.

The activists jumped on the ship and then some Libyan officials followed them, Georgoulia said.

The charity says it is an international collective of activists contributing to efforts to end Israel's blockade of Gaza, which is controlled by the Islamist group Hamas. (Reporting by Renee Maltezou in Athens; editing by Philippa Fletcher)