The "Modern Family" star announced their split in a message posted to her WhoSay page over the weekend.
"Not that anyone should care, but in order to not give the press the chance to invent hurtful drama, I prefer to tell my fans personally that Nick and I have [decided] to be apart," she wrote. "We have [been] having too many problems with figuring out how to spend time together because of my work and now his, it's been getting worse and worse, not fun anymore."
She added, "We are still very close but we believe [this] is the best thing for us right now."
Sofia, 41, and Nick, got engaged in July 2012 during the actress' 40th birthday celebration in Mexico.
The couple began dating in 2010. However, they reportedly split in May 2012, before reconciling shortly thereafter.
No big wedding had been planned, as it wouldn't have been a first marriage for either of them, Vergara told Cosmopolitan in June 2013.
"When he proposed, it was my birthday, and I'd flown more than 100 family and friends to Mexico for six days of partying. It took me forever to arrange the logistics!" she told the magazine. "If I had known I was going to get engaged, I don't do this stupid birthday."
In addition to her work on "Modern Family," Vergara has endorsement deals with Diet Pepsi, CoverGirl and many more companies.
Whilst Loeb and Vergara's engagement still appeared to be going ahead in October of last year, things had certainly changed by January. Vergara spoke to E! in October and said "We've only been engaged one year and I have to plan a very big wedding, so it's going to be when I have time to not only to plan the wedding, but then take time off after the wedding because it's going to be big." However, by January 2014, Vergara admitted on Ellen she had not had time to "even plan anything."
The Colombian beauty is currently teaming up with Reese Witherspoon for the Anne Fletcher-directed action-comedy, which stars Witherspoon as a straitlaced policewoman protecting a drug lord's sexy widow, played by Vergara, as they run from crooked cops and murderous criminals through the Lone Star State.
Filming continues full-speed ahead despite Vergara revealing over the weekend that she had ended her engagement.