Yahoo! is believed to be in talks to acquire video-streaming startup RayV to boost its web-video technology.

First reported by Wall Street Journal, the discussions currently remain private, with both companies declining to comment.

If the deal comes around, it will mark a fourth Israeli acquisition for Yahoo as it previously acquired at least three Israeli startups — Dapper, FoxyTunes and FareChase, and also boost its operations in Israel where the company already has an R&D center in Tel Aviv since 2010.

RayV offers video streaming to wireless gadgets and other devices for content providers, mobile operators and telecommunications carriers.

Founded in 2006, the video-streaming startup has been steadily growing in popularity. It recently raised more than $40 million from investors including Accel Partners, Argoquest Holdings LLC, Accrue Sports and Entertainment Ventures, Dragon Ventures and Metamorphic Ventures, reports Wall Street Journal.

If the deal comes around, it could be one among various deals being negotiated by chief executive Marissa Mayer in recent months as she aims Yahoo’s Screen video site to take on Google’s YouTube.

Though Yahoo’s acquisition talks with French video site Dailymotion as well as TV portal Hulu last year didn’t materialize, the portal had entered into discussions at the start of this year to acquire online video services Fullscreen Inc. and News Distribution Network Inc.

Yahoo also announced two new comedy shows in April and a partnership with Live Nation (LYV) to stream a live concert every day for a year.

Despite investing $1.2 billion in acquisitions and technology, Yahoo has not been able to make inroads into the online market, where its market share is increasingly being gobbled up by Facebook and Google.

Competition for the online video market is spiking, as the US online entertainment powerhouse Netflix also announced a significant expansion into Europe, promising viewers in six countries online video by the end of the year.