Business Notes FINANCE

Two stock offerings in the news last week gave investors an interesting choice: Coal or diamonds, Conrail or Tiffany?

As part of President Reagan's privatization drive, the Government sold 85% of Conrail, the freight line that hauls everything from coal to cars. The $1.65 billion stock issue, priced at $28 a share, was the largest initial public offering in U.S. history. Wall Street gave the stock a green light: on the first day of trading, Conrail was the Big Board's most active issue. By week's end shares closed at 30 3/4.

For investors more interested in bracelets than boxcars, Tiffany, the legendary jewelry-store chain, said it would sell 48% of the privately held firm. The shares are expected by early May at $21 to $23 -- lock, stock and bauble.