Battery maker C&D Technologies Inc., of Blue Bell, said yesterday that its first-quarter profit tumbled on tough comparisons to a prior-year period boosted by a gain related to the sale of a Chinese plant.

For the quarter ended April 30, C&D earned $577,000, or 2 cents per share, compared with $4.1 million, or 13 cents per share, for the same quarter in 2007.

Analysts polled by Thomson Financial expected a loss of a penny per share.

The year-ago quarter included a loss from discontinued operations of $5.2 million, or 11 cents per share, along with a gain of $15.2 million on the sale of a plant in Shanghai.

Sales rose 21 percent to $93.8 million from $77.5 million. The company attributed the sales growth to a 4 percent increase in unit volume and pricing improvements.

C&D shares rose 42 cents, or 6.6 percent, to close at $6.76. The stock has ranged from $3.70 to $7.01 over the last year.