Martin Nisenholtz, one of the newspaper industry's leading digital pioneers, is leaving the New York Times Co (NYT.N) after 16 years.

Nisenholtz, 56, plans to retire at the end of the year, according to a memo to employees on Monday from New York Times Chairman Arthur Sulzberger Jr. and Chief Executive Janet Robinson.

As senior vice president of the company's digital operations, Nisenholtz most recently helped oversee the New York Times project to start charging users to read some of it content on its flagship website and develop applications for smartphones and tablet computers.

The pay model, which was launched in March, is being closely watched by newspapers in the United States as they seek additional forms of revenue to make up for a dwindling advertising revenue.

So far, paid digital subscribers at nytimes.com and related digital products was 324,000 at the end of the third quarter, compared with 281,000 subscribers at the end of the second quarter.

When Martin Nisenholtz joined The New York Times Company in 1995, we had zero Web page views. Indeed, we had zero Web users. Further, we had no Web revenue, Sulzberger and Robinson wrote.

Today, thanks in large measure to Martin's vision and leadership, our digital numbers are dramatically different.

Nisenholtz started with the New York Times in 1995 and transforming the Grey Lady into one of the most read news websites in world.

Before he joined the Times, he worked for ad firm Ogilvy Group where he served as senior vice president and a member of the operating committee at Ogilvy & Mather Direct. In 1983 he created the Interactive Marketing Group.

Nisenholtz was not immediately available for comment.