BOGOTA, Feb 23 (Reuters) - Colombian business magnate Jaime Gilinski said his acquisition offers for shares in two companies in the country's largest conglomerate GEA could help the group's other firms raise funds to invest in their businesses and reduce debt, as he redoubled his efforts to convince shareholders to sell.

Debt reductions and renewed focus on core business by companies like industrial conglomerate Grupo Argos, will make them more attractive for possible listings on the New York or London stock exchanges - which the companies themselves have floated - Gilinski told Reuters in an interview on Tuesday.

Gilinski's conglomerate, Grupo Gilinski, has launched four public acquisition offers for shares in investment holding company Grupo SURA and food producer Nutresa, which are part of Grupo Empresarial Antioqueno, or GEA, a sprawling conglomerate of more than 100 firms.

Besides SURA, Nutresa and Argos, GEA includes bank Bancolombia, cement-maker Cementos Argos, energy generator Celsia and pension fund Proteccion. Many of GEA's companies own large portions of each other's shares.

Gilinski - one of Colombia's richest men and the owner of bank GNB Sudameris - has shaken up GEA's tightly interwoven holdings with his offers, to the chagrin of some in the conglomerate that have refused to sell shares.

If other GEA companies sell some of their stakes in SURA or Nutresa, they will have more liquidity to plough back into their own firms or to pay down debt, Gilinski said.

"These decisions (to participate in the acquisitions) will strengthen the companies. It will allow them to reduce debt, so they can concentrate on their core business and then go to the exchanges, in New York or in London or other exchanges," Gilinski said.

"It will generate important value in the future," said Gilinski, who mentioned Argos and Cementos Argos as companies that could benefit.

Gilinski and Abu Dhabi's Royal Group bought 27.7% of Nutresa shares for $980 million in an initial offer and have since launched another tender to acquire up to an additional 22.88% of the company for $10.48 per share, more than a third over the first offer price.

Gilinksi, with the financial banking of First Bank of Abu Dhabi, also acquired 25.3% of SURA for $952.5 million in a first offer and is now seeking between 5% and 6.25% more for $9.88 per share, nearly a quarter more than the first offer.

If successful Gilinski would become the largest shareholder in both companies.

Argos - which owns about 10% of Nutresa and 27.7% of Grupo SURA - and SURA both declined to participate in the first offers, arguing the price per share offered by Gilinski underestimated their value.

Grupo Argos said late on Tuesday it also would not participate in the second offers, again because it considers the price to be too low.

Grupo SURA's board is analyzing the second acquisition offers and the company told Reuters it was unable to comment while they are pending.

Some analysts agree GEA's entwined holdings must be broken up if they are eventually going to list internationally.

"Especially for foreign investors, these crossed participations are confusing because there is so much hidden value," said Laura Triana, from brokerage Acciones y Valores.

But others say changes to GEA's five-decade old structure will be difficult, especially if current owners are not interested.

"I think the current shareholders want to stay the majority and going to a foreign market will mean it won't just be Gilinski but other big business people who could absorb them," said Ana Vera, head economist at Panama's Inon Capital S.A.

Gilinski worries minority shareholders will end up with shares whose value falls after the acquisition offers.

"I worry because I think those minority shareholders, including myself, in some of the companies which have an opportunity now to sell...could lose that opportunity," he said. (Reporting by Nelson Bocanegra; Writing by Julia Symmes Cobb; Editing by Tim Ahmann)