Tetra Tech Inc. posted strong third quarter earnings Thursday, beating Wall Street estimates and sending shares up more than 13 percent.

Tetra Tech reported third quarter net income of $16.1 million (27 cents per share), 30 percent more than the $12.4 million (21 cents) the company reported in the same period a year earlier. The results beat analysts’ expectations of 24 cents per share, according to Reuters Estimates.

Sales for the Pasadena-based engineering and consulting firm surged 40 percent to $564 million, thanks in part to a 34 percent rise in federal government business. The sales results smashed Wall Street’s expectations of $304 million.

For the full year, Tetra Tech said it expects to earn 99 cents to $1.01 per share, which is ahead of analysts’ expectations of 94 cents per share.

Shares in Tetra Tech went up to $27.36 in early trading Thursday.