The head of Dubai’s metro project has resigned from his post at the emirate’s Roads and Transport Authority (RTA), according to local media reports.

The reasons for Abdul Majid al-Khaja’s resignation are unclear, but construction of the metro was delayed in 2009 by a dispute over payments between the RTA and the construction consortium building the project led by Japan’s Mitsubishi Corporation.

The dispute involves $2-3bn of claims made by the consortium, which also includes Mitsubishi Heavy Industries, Obayashi Corporation and Kajima Corporation, all of Japan, and Turkey’s Yapi Merkezi.

Tthe group submitted an initial price of $4.5bn for the deal to build the metro in 2005. However, since then the group has claimed additional costs which the RTA disputes. In 2009, the RTA acknowledged the cost of building the metro had nearly doubled to $7.6bn.

Construction work resumed in February this year after the RTA reached a settlement with the consortium (MEED 17:2:10).

An RTA spokesman declined to comment on the issue.

The RTA will open 10 of the remaining 18 stations on the metro’s Red line on 25 April.

These 10 stations include Emirates station, Airport Terminal 1 station, GGICO station, Al-Karama station, World Trade Centre station, Sharaf DG station, Marina station, First Gulf Bank station, Al-Quoz station and Ibn Battuta station. The rest of the stations will be opened in the remaining months of 2010.

The opening of Dubai metro’s Green line has also been delayed by more than a year due to a change in the design. The 23-kilometre Green line was scheduled to open in the second half of 2010 but now is delayed to August 2011.