October 8, 1981

Egyptian leaders moved quickly today to seek an orderly transition a nd to stress continuity a day after the assassination of President Anwar el-Sadat. Parliament, which is controlled by Mr. Sadat's National Democratic Party, tonight named Vice President Hosni Mubarak, Mr. Sadat's closest associate for the last six years, to succeed the slain leader as President. The nomination is subject to popular approval in a referendum in which Mr. Mubarak will be the only candidate. Although under the Constitution the referendum may be held anytime within 60 days after a presidential vacancy occurs, officials said the vote would take place on Tuesday. Effort to Stress Continuity Sufi Abu Taleb, the Speaker of Parliament, who will be Acting President until Mr. Mubarak is sworn in after the referendum, tonight appointed Mr. Mubarak Prime Minister. The appointment was seen as part of the effort to emphasize continuity and to guarantee a trouble-free transition of power. President Sadat was also Prime Minister.

The Senate approved today, by a vote of 90 to 4, a telephone deregulation bill that would free the American Telephone and Telegraph Company to expand into new data -processing and information services. For the past five years, there have been efforts in Congress to overhaul the regulations governing the telephone industry, which is dominated by A.T.& T. The bill that cleared the Senate would be the first major revision of the Communications Act since it was adopted in 1934. ''By freeing the industry from unnecessary and stifling Government controls, this bill will greatly enhance competition within the telecommunications field,'' said Senator Bob Packwood, the bill's sponsor. Senator Packwood, an Oregon Republican, is chairman of the Commerce Committee.

For millions of women around the world, the name Revlon is synonymous with the beauty business. But the company, which the late Charles Revson founded in 1932 as a nail polish business and built into the largest manufacturer of retail cosmetics in the United States, is now deeply involved in such unglamorous products as plasma derivatives, diagnostic reagents, Tums antacid tablets and lens-grinding equipment. That is not to say that Revlon has stopped pushing nail polish - or its vast range of lipsticks, eye shadows and fragrances. ''For your soul: each and every one,'' is the urgent advertising message of the House of Revlon's newest cosmetics line, Gypsy Gold, introduced last month.

Gun collectors, dealers, manufacturers and onlookers gathered yesterday afternoon at Christie's, Park Avenue and 59th Street, to bid at and watch what the auction house described as the first major auction of rifles, revolvers, shotguns and pistols in this country. The standing-room-only audience was subdued throughout, even when some of the bidding became spirited with the sale for $95,000 of a 60-year-old gold-inlaid Parker shotgun to William Jaqua, a gun dealer from Findlay, Ohio. It was a record for an American gun sold at auction and the highest price paid in the sale of 114 weapons, which also included revolvers and rifles owned by Chuck Connors, the star of the television series ''The Rifleman.'' The Winchester carbine he used in the series, which is now off the air, brought $7,500.

IT was christened Christmas in July for investors - and the Reagan tax act does bestow a host of benefits on the millions of Americans whose biggest investment is their house. Not only will the new law allow older homeowners to keep more of their profits when they sell the family home, but it will also give young people who sell their homes and reinvest the proceeds in another more time to defer paying taxes on the gain. Furthermore, the bill grants generous tax credits to investors who rehabilitate business properties, especially buildings that are certified historic structures. But the law is studded with complexities that bewilder many taxpayers. So, to help clarify the new tax act, here are some answers to commonly asked questions: Q. With all the changes in the estate law, does it still make sense to own a house jointly?