Rep. Park Geun-hye, chairwoman of the ruling Grand National Party’s interim decision-making body, vowed to curb family-owned conglomerates’ power by limiting their investment in other companies.

“We will seek to tighten the regulation over their growth with mergers and acquisitions through equity investing excessively,” she told reporters during a luncheon Thursday.

“Large companies may be the country’s growth engines, but monopolization must be prevented.”

Her remarks reflected the council’s efforts for revival of a law for a limit in large-firm investment, which was repealed in 2009 and had been advocated by the liberal camp.

The Monopoly Regulation and Fair Trade Act banned large firms from investing 40 percent or more in other companies.

Rep. Chung Doo-un, leading reformer and party policymaker, concurred with Park.

“The party council should consider reviving the restriction,” Chung wrote on his Twitter account Thursday.

During the luncheon, Park also denied speculation that the council is to ask President Lee Myung-bak to leave the party.

“We have never adopted the issue and will not make such discrimination against a specific member,” she said.

By Bae Hyun-jung (tellme@heraldcorp.com)