Universal has announced plans for the fourth Jason Bourne instalment and hired the franchise’s key writer Tony Gilroy.

Gilroy will write a treatment for the project, tentatively called The Bourne Legacy although not based on the book of the same name written by Eric Lustabader. Universal has set a 2012 release.

Gilroy will also write a Bourne franchise “bible” to record the cast of characters and key elements in the Bourne world and ensure consistency throughout the series.

Frank Marshall and Pat Crowley return as producers alongside Captivate Entertainment’s Jeffrey Weiner and Ben Smith.

The studio did not have an update regarding director and star. Paul Greengrass, who directed the last two films, went on record last year saying he had no plans to return to the series. Damon said he would only do so if Greengrass were on board.

The last instalment, The Bourne Ultimatum, went on release in August 2007 and earned more than $440m worldwide.