The span was placed on piers 14 and 15 at the Mawa end around 10:25 am on Saturday, said Dewan Abdul Kader, executive engineer of the Padma Multipurpose Bridge.
The installation of the 150-metre-long span has made 1950 metres of the bridge visible, which will stretch to 2.15 km after the installation of the next two spans.
A floating crane carried the span from a construction yard at Kumarbhog on Friday morning but its installation was delayed until Saturday due to bad weather, said Md Humayun Kabir, deputy assistant engineer at Bridges Division.
The first span of the bridge was installed on Sept 19, 2017 and the second was installed on Jan 28, 2018.
The bridge will have a total 42 piers and 41 spans, each 150 metres long and weighing up to 3,140 tonnes.