A French-owned oil company is going ahead with its acquisition of Texasgulf Inc., an important U.S. minerals and petroleum producer, despite a request from the Reagan administration to delay the takeover attempt.

The Committee of Foreign Investment in the United States, an interagency administration panel, has asked for more time to study the purchase of Texasgulf stock by Societe Nationale Elf Aquitaine, two-thirds owned by the French government.

But the answer is no. "We are pursuing the purchase of shares," a spokesman for Elf Aquitaine in New York City said yesterday. Texas shareholders have until midnight next Monday to act on the French company's offer of $56 for each share of common stock and $178.49 for preferred stock.

The committee, headed by the Treasury Department, can only request a delay, since it has no statutory authority to intervene.

The committee, headed by the Treasury Department, can only request a delay, since it has no statutory authority to intervene.

But the intervention by the committee, which has not been very active in the past two years, adds new heat to the simmering issue of foreign investment in U.S. energy companies.

Elf Aquitaine's partner in the takeover attempt is Canada Development Corp., an investment company controlled by the Canadian government, which already owns 37 percent of Texasgulf stock.

If their plan succeeds, CDC would wind up with control of the Canadian properties of Texasgulf and Elf Aquitaine, furthering Canada's new policy of concentrating control over its energy resources in Canadian hands. Texasgulf's Kidd Creek mine in Canada is believed to be one of the richest lodes of copper, silver and zinc in the world.

Canada's policy has triggered a growing political reaction in Congress. Today, Interior Secretary James Watt is scheduled to testify before a House Commerce subcommittee on possible retaliation by the United States against Canadian takeover moves such as the Elf Aquatiane-CDC acquisition and the bid by Seagram Co. to acquire 51 percent of the stock of Conoco Inc., the ninth-largest U.S. oil company.

If the Interior Department concludes that Canada's policies discriminate against the United States, in violation of a reciprocity requirement in the U.S. Mineral Leasing Act of 1920, a range of sanctions could be ordered, including limiting or forbidding firms with substantial Canadian ownership from obtaining mineral or petroleum leases administered by the department.

Another sore spot in U.S.-Canadian energy relations developed yesterday when Nu-West Group Ltd. of Calgary said it is seeking nearly $1 billion in damages from Cities Service Corp. and Cities' president, Charles J. Waidelich.

Cities Service, a Tulsa-based oil company, has brought suit in U.S. District Court to oppose Nu-West's efforts to purchase its stock.

In a counterclaim, Nu-West charged yesterday that Cities Service and Waidelich have "embarked on a campaign through the press, their lawsuit against Nu-West, their letters to Cities Service shareholders and other methods to thwart Nu-West's lawful right to purchase and exercise ownership of Cities Service common stock.