Hyundai Heavy Industries (HHI) Group is stepping up efforts to adopt a holding company structure to streamline its business portfolio and bolster its corporate value.

The group said Tuesday that Hyundai Robotics, the de facto holding company, will issue new shares, worth 1.77 trillion won ($1.57 billion), to buy stakes of its three affiliates – HHI, Hyundai Electric and Hyundai Construction Equipment – to become a holding company.

Currently, Hyundai Robotics has a 13.37 percent stake in each of the three firms but to become a mother company, it must hold more than 20 percent under the country's Fair Trade Act.

Hyundai Robotics plans to ask shareholders of HHI, Hyundai Electric and Hyundai Construction Equipment to return their shares in exchange for its shares. The exchange ratio will be determined by the end of July.

"The latest rights offering is aimed at turning Hyundai Robotics into a holding company. We expect many shareholders will be willing to swap their shares in HHI and the other two for those of Hyundai Robotics," an HHI official said. "Sales manager NH Investment & Securities will ask shareholders to switch shares in mid-July. If everything goes as planned, Hyundai Robotics will have as many as 27.87 percent stakes in each of the three affiliates."

On Tuesday, shares of Hyundai Robotics fell 5.22 percent, or 21,500 won to 390,500 won per share, while HHI shares jumped 4.24 percent, or 7,500 won to 184,500 won. Shares of Hyundai Electric and Hyundai Construction Equipment fell 1.85 percent and 1.41 percent, respectively.

Asan Foundation Chairman Chung Mong-joon has a 10.16 percent stake in Hyundai Robotics, followed by Hyundai Mipo Shipyard with 7.98 percent and Asan Foundation with 2.53 percent.

On April 1, Korea's largest shipbuilder was split into four units in a bid to strengthen the core competence of the shipbuilding and other business divisions, as well as improve their financial health. HHI runs shipbuilding, offshore plants and engine operations, with three other firms managing their respective areas of business.

Analysts say Hyundai Robotics shares will likely head upward once the rights issue is completed.

"Until the exchange ratio is fixed, the shares of Hyundai Robotics and its affiliates will likely fluctuate sharply," Meritz Securities analyst Kim Hyun said. "But after the swap is completed, Hyundai Robotics will attract greater attention from investors for its growth potential as HHI Group's holding firm."