Joining the Nielsens has been good to Spanish-language webs Univision and Telemundo.

The rivals saw an uptick in ratings during the February sweeps, with market leader Univision claiming it out-delivered at least one of the Big Four webs among adults 18-34 on 16 out of 28 nights.

NBC Universal-owned Telemundo touts the fact that it is the only Spanish-language web registering primetime growth over last year in both the adults 18-40 and 18-34 demos.

During the Feb. 23 finale of Univision’s Sunday ratings winner “Bailando por un sueno” (Dancing for a Dream),” web became the third most watched network among adults 18-34 (with 2 million viewers) and kids 2-11 (879,000), bested by ABC’s own “Dancing With the Stars” and the final telecast of NBC’s Winter Olympics coverage.

“Bailando’s” finale helped Univision achieve its highest Sunday 7 p.m.-11 p.m. performance ever among adults 18-34 and 18-49.

The 7 p.m. novela “Piel de otono” (Autumn Love), which ended on Friday, Feb. 17, became Univision’s highest-rating 7 p.m. novela ever among adults 18-34 (1.3 million) and 18-49 (2.2 million).

The web’s main programming supplier, Mexico’s Televisa, produces “Bailando ” and “Piel de otono.”

Web’s nightly inhouse network news program “Noticiero Univision” delivered its highest adults 18-34 and 18-49 performance compared with any February sweep.

Attracting an extra 160,000 adults 18-49 and 114,000 adults 18-34 viewers in February over the same month last year, Telemundo is the fastest-growing broadcast network for primetime weeknights in those demos.

Telemundo’s new original telenovela “Tierra de pasiones,” scored nearly 1 million adults 18-49 viewers, making it the highest-rated premiere for an 8 p.m. novela and the second highest rated premiere ever for the web.

With its 24% share of Spanish-language broadcast television, Telemundo lags way behind its rival, but it has reported a 23% jump in ratings from February 2005 in adults 18-49 and a 32% rise in 18-34.

Univision joined the Nielsens in December while Telemundo came onboard Feb. 1. Univision’s sister channel Telefutura joined the NTI on Feb. 27.