OSLO (Bloomberg) ? General Maritime Corp., the second- biggest US oil-tanker company, rejected a $1.5 billion takeover bid from Frontline Ltd., saying it was too low, and adopted a plan to deter further offers for the company.

Frontline offered $39 per share, according to a November 30 letter to Genmar?s board, Genmar said in a PR Newswire statement today. The offer was 7.8 percent higher than the average share price during the 30 business days before the close of trade on November 29, Frontline said in the letter. Bermuda-based Frontline dropped the offer after the rejection, Tor Olav Troim, a Frontline director, said yesterday by telephone from London.

?The premium is not a serious offer for the control of a company,? said Natasha Boyden, an analyst at Cantor Fitzgerald LP in New York, who rates Genmar shares a ?hold?.

Frontline, the world?s biggest oil-tanker company by capacity, said December 1 it held a ten percent stake in New York- based Genmar and that it would take steps to begin talks on a combination. A takeover of Genmar would be the biggest ever in the oil-tanker industry, based on today?s valuations, and increase Frontline?s capacity to about 21 million tons of crude, equivalent to five days of OPEC production.

?The Board reviewed Frontline?s proposal and concluded that it does not reflect the underlying value of the company and is not in the best interests of our shareholders,? Genmar?s chairman and chief executive Peter C. Georgiopoulos said in the statement today.

Shares of Genmar fell as much as five percent to $38.46 in New York yesterday.They rose 6.7 percent to $41.22 on December 1. Shares of Frontline fell two percent to $42.37 and traded as low as $42.15 in New York. They closed 1.4 percent lower at 284 kroner ($42.42) in Oslo.

?The rejection doesn?t seem to create value for Genmar shareholders as the stock is down,? Troim said. Troim didn?t rule out the possibility of the offer being revived if there is sufficient interest from Genmar shareholders.

Frontline bought an initial stake in Genmar a year ago, and later raised the holding saying it may bid for the rest of the company. Genmar also rejected that approach, prompting Frontline to cut its stake.

Frontline made no public announcement of the bid because it preferred to discuss its ideas with Genmar?s board on a confidential, non-public basis, according to the letter included in Genmar?s statement yesterdayday.

Genmar?s response is hostile, according to Rachid Bendriss, chief analyst at Carnegie ASA in Oslo. Genmar published Frontline?s letter even though the company asked that it be kept confidential, Bendriss added.

Genmar?s board approved a plan to give shareholders as of December 7 the right to purchase one share in the company for every one already held ?to assure? that all receive ?fair and equal treatment? in the event of an offer.

The plan is designed to ?guard against partial tender offers, squeeze-outs, open market accumulations and other abusive tactics to gain control?, the company said. It ?is not designed or intended to prevent an acquisition of General Maritime on terms that are favourable and fair to all shareholders?.

Genmar?s board may evaluate the plan within 12 months of its adoption, it added. The rights will not be triggered as a result of a qualified offer, the company said.

?This is a poison pill to make it harder to complete a takeover,? said Arne Egil Roenning, an analyst at Fondsfinans in Oslo, who recommends investors sell Frontline shares.