The £88m-turnover company was asked to make a stock exchange announcement after a sharp rise in its share price led to speculation that a buyout offer had been made.
In a statement, Swan Hill said it had received a number of "unsolicited" approaches.
Swan Hill comprises a commercial property and a housebuilding division. It is thought the business is unlikely to be sold whole and that buyers will target its housebuilding operation.
It is understood that the company will fight any split, with management believing the combination gives the company the ability to weather downturns in either market.
The housebuilding division earned a £2.7m operating profit on turnover of £17.4m in the six months to 30 June 1998. At the interim stage last year, the company's landbank stood at 904 plots with planning permission. The larger property arm made an operating profit of £1.2m on turnover of £23.8m in the same period.
Chief executive John Theakston could not be contacted for comment.
Potential buyers are thought to include Crest Nicholson, Wainhomes and Taylor Woodrow.
Swan Hill's shares ended on 77p last week.
