Nomorobo, a Mount Sinai-based startup that blocks telemarketing calls, has received an endorsement from telecom giant Time Warner Cable Inc., which announced it would give its phone customers easy access to its third-party robocall-blocking service.

Time Warner introduced the option last week for customers to opt into Nomorobo’s service with a single click on the telecom’s phone management website. Previously, customers had to go through Nomorobo separately to use its call blocking offering.

Since Time Warner announced the new sign-up feature on Thursday, Nomorobo has added 3,200 users, bringing the company’s total users to more than 384,000.

While the partnership carries no direct monetary value for Nomorobo — the service is free for Time Warner customers — company founder Aaron Foss said it is an acknowledgment of the usefulness of the service.

“I got this multibillion company to say ‘Hey, we’re going to tie into this tiny, insignificant company’s service,’ ” Foss said.

To date, Nomorobo has blocked nearly 61 million calls since its founding in late 2013, he said.

advertisement | advertise on newsday

Foss’ patented technology relies on a landline feature known as simultaneous ring, an evolution of call forwarding.

When customers receive a call to their landline, some phone carriers allow that call to ring on several phones at once. Nomorobo can be added to the list of phones that receive the call. Using its growing list of 174,000 blacklisted robocallers, it evaluates the call before automatically hanging up on an incoming robocall after one ring.

“With robocalls being the largest category of complaints at the Federal Communications Commission, we want to do everything we can to empower our customers to take control over the calls that come into their home,” Jeff Lindsay, general vice president and general manager of TWC Home Phone said in a statement.

Foss said Time Warner’s endorsement of Nomorobo will help introduce his company’s upcoming premium service — expected to launch in four to six weeks — to more customers.

For $5 a month, the premium service will allow customers to see a log of who has called, who was blocked, add or remove numbers to their own blacklists, and identify robocalls to mobile phones, he said.