A British industrial company yesterday pulled out of a $15.3 million deal to acquire a 24 percent interest in Washington Homes of Waldorf, Md., citing changes in stock market conditions.

Scottish Heritable Trust said it did not intend to exercise its option to acquire 900,000 shares of Washington Homes at $17 a share from company chairman William J. Harnett and president Lawrence M. Breneman. Washington Homes owns 89 percent of Washington Savings Bank in Waldorf.

Washington Homes, selling at $9.13 a share when the deal was announced in August, currently is at $11.75, after rising to $17. A source said the British company felt conditions were no longer as favorable as before.

Also, the Federal Home Loan Bank Board, which regulates federal thrifts, asked for additional information about the amount of control Scottish Heritable Trust would exercise over Washington Homes.

To respond, the British company apparently would have needed more time than allowed by the 90-day option period.

While the Trust deal was pending, other buyout offers came from Sonny DeCesaris & Sons of Clinton, Md., and from Preference Homes II LP.

The offers are being reviewed by Thomson McKinnon Securities, the investment adviser to Washington Homes.