Ubisoft doesn't expect to sell as many copies of Assassin's Creed 4: Black Flag as last year's Assassin's Creed 3, the publisher has said.

The warning came during Ubisoft's FY13 earnings call last night, where it was revealed that Assassin's Creed 3 had managed to ship 12.5m units.

"To come back to Assassin's Creed 4, in our numbers we have... we expect less than last year," Guillemot said (as reported by GameSpot).

"We are actually pushing to achieve more than last year because we think the pirate segment is a great segment that can generate a lot more on a worldwide basis than what was achieved last year," Guillemot said. "But we wanted to be prudent on our expectations so that it can probably be a bonus if it comes."

Ubisoft hasn't said why it believes Assassin's Creed 4 sales may not topple those of Assassin's Creed 3, but the release of Watch Dogs shortly after may play a role.

The highly-anticipated open-world cyber thriller is due to go on sale just three weeks after Assassin's Creed 4 hits stores on November 1.

Source: GameSpot