Chris LaRosa, YouTube’s product manager for music who had been leading the site’s efforts to launch a subscription music service, is leaving the company to join a small startup, a Google source confirmed.

A YouTube rep declined to comment. The departure of LaRosa, a seven-year veteran of Google and YouTube, was first reported by the Wall Street Journal.

Since joining the company in 2007, LaRosa has been a key part of building YouTube’s music business, responsible for working with record labels and leading the deal to have YouTube video metrics incorporated into the Billboard Hot 100 chart last year. The startup he is joining is not in the music industry, according to the source.

YouTube still has a large team working on the subscription service, but LaRosa’s exit — which comes on the eve of its expected launch — is seen as a blow to the initiative.

YouTube plans to launch the paid-music service within the next few months, which is being designed to provide streaming and offline access to songs across multiple devices. It will be integrated with Google Play Music All Access, the $10 monthly service introduced last year, according to sources familiar with the plans.

As of last month, YouTube said it had inked pacts with music companies representing 95% of the industry, including the three major labels: Universal Music Group, Sony Music Entertainment and Warner Music Group.

Several indie labels have not agreed to YouTube’s terms for subscription service, seeking more favorable financial terms. But as music companies’ previous contracts with YouTube expire, they must either sign a new commercial contract (which encompasses the paid-music service) or agree to the noncommercial terms of service (in which case their content will not carry advertising) — otherwise, their content will be removed.

LaRosa reported to Shiva Rajaraman, director of product management for YouTube. With LaRosa’s departure, the product managers working on the subscription-based music service — including those covering advertising, paid and mobile areas — who previously reported to LaRosa will now report to Rajaraman.