The European Union has restarted its competition investigation into the $1.8bn merger between Hyundai Heavy Industries (HHI) and DSME.

The probe into the tie-up between the South Korean shipbuilding giants was halted on 31 March as it waited for the companies to provide further information.

The previous deadline has been 7 May, but a decision is now set for 3 September.

In December, the EU warned that the move could push up prices due to the companies having a combined market share of 21%.

It was also concerned that it would stifle innovation in the sector.

Missing information supplied?

"Once the missing information is supplied by the parties, the clock is restarted and the deadline for the Commission’s decision is adjusted accordingly," the European Commission had said in March.

The EU executive body had said some companies had been struggling to provide the necessary information during the coronavirus pandemic. It was not clear whether this had affected HHI or DSME.

A Hyundai Heavy official said it was "maintaining a constructive dialogue" with the EC during the suspension.

The commission announced the probe in December. The acquisition was proposed in March 2019, with the duo hoping to complete the deal in the first half of 2020.

HHI and DSME are also awaiting the result of competition investigations in its home country, as well as Japan, China and Singapore.

So far, only Kazakhstan — necessary due to DSME's oil production unit business in the country — has okayed the acquisition.

Japan is seen as the biggest obstacle to a potential tie-up, given its issues with South Korea's purported state aid for shipyards. Unions also oppose the deal.