Increased sales and the opening of new stores helped Trak Auto Corp., the auto-parts retail chain controlled by Washington's Haft family, boost its profit 81 percent in the first six months of its fiscal year.

For Crown Books Corp., the 257-store book retail chain also controlled by the Hafts' Dart Group Corp. holding company, earnings also increased -- 23 percent in the first half and 48 percent in the fiscal second quarter. But its increases appeared to stem mainly from a one-time gain on the disposition of its stock in Bookstop Inc., an Austin, Tex.-based retail chain that reached an out-of-court settlement with Crown over Crown's 1989 attempt to buy the company.

Trak, which operates 325 stores throughout the country (compared with 296 stores a year ago), said sales at its stores open more than a year rose 5.6 percent in the fiscal first half, ended July 31.

Landover-based Trak said it made a profit of $2.06 million (36 cents a share) in the fiscal first half, compared with $1.14 million (20 cents) in the same period a year ago. Its revenue increased 11.7 percent, to $143.8 million from $128.7 million.

The company earned $1.1 million (20 cents) in the second quarter, up 34 percent from a profit of $843,000 (15 cents) in the same quarter a year earlier. Revenue rose 11 percent, to $76.2 million from $68.7 million.

Landover-based Crown reported a first-half profit of $3.5 million (67 cents), a 23 percent increase from profits of $2.85 million (55 cents) in the year-ago first half. Revenue was $93.6 million, up about 11 percent from $84.5 million in the same period of fiscal 1989.

Crown earned $2 million (38 cents) in the second quarter, compared with $1.35 million (26 cents) in the year-ago quarter. Revenue rose about 9.5 percent, to $48.9 million from $44.7 million.

Crown reported a pretax gain of $1.83 million on the disposition of the Bookstop shares, less certain expenses. Crown had reached an $8.3 million out-of-court settlement with Bookstop, which has 22 "superstores" in Florida, Louisiana, Texas and California, over the 1989 acquisition bid.

Crown acquired 20 percent of Bookstop and then made a $40-per-share offer for the remaining shares. Bookstop executives then sold a 60 percent stake in the company to BDB Co., parent of Crown rival B. Dalton, for less than $40 a share. Crown later opened its own "superstores" under the "Super Crown" name.