DocuSign trimmed its full-year outlook for billing, after the closely-watched metric fell short of its guidance in the first quarter.

The San Francisco e-signature company on Thursday posted a profit of $72.1 million, or 34 cents a share, compared with $33.8 million, or 16 cents, a year earlier.

Adjusted earnings were 90 cents a share. Analysts polled by FactSet expected 81 cents a share.

Revenue rose 8% to $763.7 million, ahead of the company's projection for as much as $749 million. Analysts were looking for $748 million.

Billings rose 4% to $739.6 million. The company had projected the metric to come in between $741 million and $751 million.

For the year, it now expects billings of around $3.3 billion, down from its prior forecast of as high as $3.4 billion.

Shares fell 17.8% to $76.4 in post-market trading following the results.

DocuSign expects third-quarter revenue of $777 million to $781 million, ahead of the $774 million expected by analysts.

For the full year, DocuSign now expects sales between $3.15 million and $3.16 billion, up from its prior view of $3.13 billion to $3.14 billion.

DocuSign's board also authorized up to an additional $1 billion for its share repurchase program.