DANBURY, Conn. (AP) _ The Federal Trade Commission removed an obstacle to the sale of some Union Carbide Corp. manufacturing sites to Arco Chemical Co.

The two companies will each pay the federal government $1 million under a consent order the FTC issued Wednesday for the sale Carbide's urethane polyols and propylene glycols manufacturing plants in West Virginia for $220 million.

The sale was announced in September 1989 but the FTC sought a preliminary injunction halting the sale in June after the agency raised questions about whether the companies properly notified it about the proposed merger.

Under the Hart-Scott-Rodino Act, companies must notify the FTC about mergers, giving the government time to identify possible consequences of reducing the number of competing manufacturers.

The preliminary approval issued Wednesday calls for a 60 day public review period. The formal transfer is expected to take seven days after that.

''We're pleased. We obviously had a choice of whether to participate or not,'' said Earle Bradford, a spokesman for Pennsylvania-based Arco, a unit of the Atlantic Richfield Co.

James Moore, a Carbide spokesman, said that despite the FTC's delay, the businesses continued operating. The Carbide plants employ about 139 workers, mostly in West Virginia.

''The only thing that has held up was the transfer of assets to Arco,'' Moore said. Arco paid for the sites last year.

Urethane polyols are used to make polyurethane foam found in furniture cushions and other products. Propylene glycols are used to make personal care products and cosmetics, automotive antifreeze, pet foods and liquid detergents, among others.