Waters Corp., a maker of scientific instruments, on Wednesday said second-quarter profit increased by 21 percent as revenue rose, partly on demand for new products.

The company earned $84.9 million, or 90 cents per share, compared with $69.9 million, or 72 cents per share, in the same period a year ago.

Excluding one-time items, Waters earned 93 cents per share, up from 78 cents per share.

Revenue rose by 8 percent to $391.1 million. That's higher than the $389.5 million that analysts had projected, according to Thomson Reuters.

Waters' profit after one-time items also exceeded analysts' forecast of 90 cents per share.

Shares of Waters, based in Milford, Mass., rose by $2.87, or 4.6 percent, to $65.61.