Wall Street security analysts are taking a cautious approach to speculation about Utah industrialist Jon M. Huntsman's intentions regarding the Aristech Chemical Corp., and the company is doing likewise.

Last week, Aristech announced that Huntsman had made known his intention to acquire in excess of $15 million but less than 15 percent of the Pittsburgh-based company's stock.The announcement was followed by a sharp increase in the price of Aristech stock, which soared 63/4 Thursday on the New York Stock Exchange to close at 381/4. On Friday, Aristech stock closed at 371/2, down 3/4.

Huntsman Chemical is the world's largest producer of polystyrene plastic, which is used in applications ranging from egg and fast food containers to television cases and car dashboards.

Huntsman, who abandoned a brief candidacy for the Utah governorship to expand his business last year, has said Huntsman Chemical has annual sales of around $1 billion.

Aristech, a 1986 spin-off from USX Corp's chemical division, produces plastic products, including polypropylene plastic and industrial chemicals such as phenol and acetone.

Securities analysts who follow Aristech are wondering whether Huntsman simply plans to invest in the company, or whether the announcement was a prelude to a hostile takeover attempt

Aristech officials have declined further comment and Huntsman is traveling out of the country, his office said.

Brent Stevenson, president of Huntsman Holdings Corp., described the speculation as "unfortunate."

"Everyone speculates a lot. But intent is one of those things that changes depending on where things go and I really can't say anything at this time."

J. Jeffrey Cianci, a securities analyst at Bear Sterns in New York, said Huntsman's motives are unclear.

"This is not necessarily a hostile move, although it very well could be," he said.

However, Cianci said, it seems odd that if Huntsman is contemplating a hostile takeover, he would do so at a time when Aristech's revenues and profits are at record levels.

Aristech last year reported sales of $1.07 billion and earnings of $188.2 million, or $7.57 a share, up from the previous year's revenues of $918.8 million and net income of $69.7 million.

Fiscal 1988 earnings results included a $23.7 million gain from an accounting change.

Securities analyst Robert S. Reitzes of Mabon, Nugent said Aristech is an attractive company with a strong revenue and earnings performance.

"I don't think anyone has a clear fix on this and it looks like we're going to have to just wait and see what develops," he said.

Yet another analyst, who requested anonymity, said Aristech possesses elements that would fit well with Huntsman Chemical.

"It all depends upon what Mr. Huntsman's motives are," the analyst said. "Mr. Huntsman could just see Aristech as an attractive investment. Maybe he wants a seat on the company's board."

Aristech's name has surfaced in rumors as a possible takeover candidate in the past year, and some analysts have pointed out that chemical producers in general are considered attractive because of their strong profits and distinctive business.

Aristech said Huntsman had informed the Federal Trade Commission in a Hart-Scott-Rodino filing of his intention to acquire and hold shares of Aristech common stock valued in excess of $15 million, but not more than 14.999 percent of shares outstanding.

Under the Hart-Scott-Rodino anti-trust law, Huntsman is required to make the filing and wait 30 days before he can proceed to acquire Aristech stock with a value in excess of the $15 million mark.