EuroGas Inc., a New York-based company that controls major methane gas development concessions in southern Poland, said Kamehameha Schools/Bishop Estate has obtained an option to buy 2 million EuroGas shares. The amount of the investment could be as low as $7 million and as high as $12 million, depending on when the option is exercised.

EuroGas said the estate may buy the shares at $3.50 each if it does so within 90 days after a pending agreement is reached between a Polish subsidiary of EuroGas and Texaco Inc. to take the gas out of the ground.

If the investment is later than 90 days, Bishop will pay $4.50 a share. If it is after 1997, the estate will pay $6 a share until the end of 1988, when the option expires.

If the shares are purchased, it will be a relatively small investment by the estate's standards.

The estate reported assets of $1.7 billion for its last reporting year, 1994. Outside observers, including the Wall Street Journal, have estimated assets closer to $10 billion.

The estate had no comment on the investment and EuroGas said the terms of its deal with the estate are confidential.

EuroGas shares were trading at $4 today, according to Bloomberg Business News.