Restoration Hardware Inc., a retailer of upscale home furnishings and tools, expects to offer 3.33 million shares at $16 to $18 apiece in an initial public offering. The Corte Madera-based company filed for the IPO with the Securities and Exchange Commission in April without specifying the size or price. After the IPO, new investors will own about 21% of the 16.1 million shares outstanding, according to an amended SEC filing. A midpoint per-share price of $17 implies a market value of about $273.7 million. Restoration now has 44 stores in 21 states. It plans to add 25 stores this year and 30 in 1999. The company expects to raise about $42.6 million after expenses in the IPO and use about $28 million to repay debt. For the three months ended May 2, Restoration reported a loss of $746,000, or 18 cents a share, compared with a loss of $542,000, or 11 cents, in the year-earlier period. Revenue almost tripled to $32.6 million from $11.9 million. Restoration expects its shares to trade on Nasdaq under the symbol RSTO.