The span installation began at 7am on Sunday, project engineers said.
The 150 metre span, which weighs 3,140 tonnes, was placed on top of the piers at 8am.
The first span of the bridge was installed on Sept 30 of last year between pillars 37 and 38 on the Jazira side.
The second was installed on Jan 28 between pillars 38 and 39, while the third was placed between pillars 39 and 40 on Mar 11.
The government is aiming to finish construction work on the bridge by the end of 2018. Bangladesh has signed a $2.76 billion dollar loan deal with China’s EXIM Bank to implement the rail line project on the bridge.